Change of career from engineering to anything else academic.

You answered to your dilemma question. It is being teacher or lecturer. All you need to do specialization by doing M.Tech. Instead of back thinking . Think what you can do more for your dreams. If M.Tech. not possible then MBA is also good option. Not necessary you have to do corporate job but yes experience is necessary to start own venture. Nowadays there are lot of franchise to give you business but for that your will need money. So you see lot of option just be positive about next action. Start might be bad but journey is fruitful.

You have narrated your education career in details and your unhappiness about it.

In fact, one should choose a line where one has interest and aptitude so that one can willingly and happily work hard in that career line and progress and prosper.

Right now, you appear to have some good options with you. First one is you can go for some diploma or certificate course in computer related areas like networking, system management, software development, database etc. Then you can apply in the industry for some related and appropriate job.

Another thing is you can go for M.Tech. after which you can appear for NET and after qualifying it you can apply for lecturer ship in colleges. Even if you do not qualify in NET you can try to get teaching job in private colleges where NET is not so much insisted.

There are some other areas where you can think of venturing if it corresponds with your temperament. One of them is joining some tutorial or coaching center. Another is starting one's own work like business or service in computer related areas.

Now a days there are opportunities in online selling and other business models which can be attempted for a long time perspective.

So other than core engineering, there are many things for making a career. The list is endless.

Have you interest in office jobs like subordinate/ assistant level services. If so then you can attempt to appear for state or central Govt posts which are advertised time to time. Many PSUs and other quasi Govt departments also advertise posts time to time and if any of that matches with your expectation, you can venture in that arena also.

You are many options before you.
1. B.Ed., You can take admission in B.Ed and after completing B.Ed you can go for teaching in any school. There you can teach mathematics and Physical sciences to high school students. This will be the easiest way to look at. B. Ed can be completed by Distance Education while you are working.
2. M.Tech. You can go for M.Tech and then appear for NETexamination to get qualified for Lecturer post with UGC Scales. If you qualify in NET for the research, you can try for PhD with CSIR/UGC fellowship
3. Otherwise, with M.Tech you can join in any private college and registered for your PhD in any university under part-time. After completing the PhD you will become eligible for lecturer post with UGC scales.
4. You can do some diploma or PG diploma course in Computer applications and you can try for a related job in private industries.
5. You can also work differently in the HR department or administration department by getting a diploma in Social work or IRPM or HR.

There are the various options I prefer to consider and from this, you can decide on the best possible choice for your future career. All the best to you.

Below are some of things you can do in order to pursue your career dream:-
1) Do post graduate course so that you are eligible for a Post graduate teacher or an assistant professor.
2) You must clear NET/JRF in order to apply for Assistant Professor post in government colleges. So do clear it after your PG course.
3) Yu can even apply for Scientific assistant post which come up and get into some research oriented stream.
4) Always apply for PSU jobs. The main benefit is that you are paid well and there is a good working environment.
5) Without thinking much apply for a PG degree and start preparing for the PSU exams.
6) The syllabus for all technical is more or less the same as GATE syllabus.
7) Best of luck

Though you have done your graduation in Mech Engineering and still you are not satisfied with this achievement since it does not match with your passion. I would suggest a few options which you may like and at the same time it will brighten your career - prospects. Points are listed as follows -
1) Take up M.Tech course by clearing GATE with an impressive percentile so as to secure a seat in a premier institution and later by clearing NET, you can join in the teaching profession in a government college.
2) You can look around your locality and see how far you can be successful in imparting coaching to the aspirants interested in clearing the entrance test in engineering. Choose any one of the three subjects for which you have ardent passion namely Physics, Chemistry and Mathematics and indulge yourself in brightening the career of the aspirants. Initial years could be the trying phase but later you will achieve both money and fame.
3) PSU are looking for energetic candidates having impressive scores in each stage of their studies and by having a M.Tech degree in Mech Engineering, you will be rewarded with two advanced increments in the pay - structure and in addition to this, you may like the competitive environment.
4) If you want to go in the Research - wing. You may chooseeither ISRO or Atomic Energy Commission for your ultimate destination.
5) If you want to achieve a career which would envy your friend circle, go in for IAS with your hard preparations and ultimately such an achievement will stimulate you in many ways.

I have read the details. In India, many students face this sort of problem. They are forced to attend the course which they don't like. Sometime they themselves take admission in such courses which they find boring or uninteresting due to so-called career prospect. You studied mechanical engineering because you thought that it has good prospect, but you didn't introspect before taking admission whether you are meant for this course, or not.

After four years you have three options. Option No. 1 is to study any of those subjects which you like. This option can be accepted if your family have sufficient financial stability to bear your cost for another 5 years or so. Option No. 2 is to go for M.Tech/M.E and join faculty position in any engineering college. If you don't like the subject, this option is also not advisable. Thirdly, you can join any coaching institute for entrance examinations and start teaching Mathematics. Nowadays, good teachers in such coaching institute earn in lakhs (of course, if they can prove their mettle).

Choice is yours!

From your answer, it does appear that you are not at all interested in Mechanical engineering. You have also indicated that you have a taste for computer science and mathematics.

There are some suggestions here. Continue to take tuition for Mathematics and even the first and second mathematics of the Degree standard. Hundreds of students find mathematics a very difficult subject to handle and hence they will automatically come to you.

It is also advisable to take up a short term course in a new subject like SAP Marketing or SAP Finance or SAP Supply Chain Management. You are most likely to get a job. Please do note, the final examination of the SAP is very costly and may cost you upwards of two lakh rupees. If you can afford this, fine. Go ahead.

Otherwise, take up this course in the evenings in a local institute where they charge you something like Rs.25,000 to be paid in installments. Once you get a certificate, go over to Mumbai or Bangalore ( you have not mentioned where you are from) and you will get an entry job. With experience, you can scale up and depending on your expertise and talent, they will pay you more. With SAP Marketing, you may get a job with any company that is into some sort of Marketing. Even the likes of Big Bazaar may have vacancies. SAP Supply Chain Management is the in-thing. There is a huge scope here. The transportation of goods can never stop. The economic engine has to roll on.

Supply Chain Management is crucial. You can easily find a job with the likes of companies like TVS Logistics.

With experience, you will have gone into another orbit. Yes, there are many like you who are misguided at some stage. However, it is very much possible to go ahead in life.

Now, coming back to the teaching part of it. Once you gather the vital experience, you can join as part time teacher of SAP in any institute. In fact, there is a huge demand in the metros like Bangalore, Chennai, Hyderabad and New Delhi. You can easily have the best of both worlds. The industry experience is suggested only because only that will enable you to go ahead in life.

Go into this orbit. You will be happy.

All the best.

I don't think you have wasted your time, from my viewpoint, you have a B.E degree and a job. There are many people who do not have either or both of them.

OPTION:1
A.Since you are keen on teaching and already taking tuitions. I suggest, first continue the tuitions.
You need some form of a formal training and degree in teaching so that you can switch to become a full-time teacher.

B.I feel that it would wise to consider a distance mode B.Ed (http://www.ignou.ac.in/ignou/aboutignou/school/soe/programmes/detail/90/2)

Some other courses that can be considered are
Diploma in early childhood education programme leading to Diploma in Preschool Education (DPSE).
Elementary teacher education programme leading to Diploma in Elementary Education (D.El.Ed.).
Bachelor of elementary teacher education programme leading to a Bachelor of Elementary Education (B.El.Ed.) degree.

C. The other option to consider is from next year, the Government is planning to introduce a dual degree B.Ed program wherein you get a B.A+B.Ed, B.Com+B.Ed, this is a four-year program.

D. Once you complete either B or C, you can write the TGT exams and enroll as a teacher in Maths or Physics that are your core good subjects. At the same time, you can continue taking tuitions.

E. With a B.Ed and a teacher's job, you can again consider a distance mode Masters and a PhD in education. By the time you complete these two, you would have sufficient experience to become a senior school teacher and then move on to become a principal etc. IGNOU has a Post-Graduate Diploma in School Leadership and Management (PGDSLM), that is designed for good teachers to become school leaders.

OPTION:2

A. Keeping in mind that you like maths and physics, you can consider the Integrated MSc-PhD in Physics and Astrophysics (IPHDAP) offered by IGNOU, this will enable you to advance your prospectus of becoming a teaching faculty.

B. You can also consider an M.Tech computer science and then take up the UGC NET/ SET exams that will give you the opportunity to become a lecutrer or assistant professor in physics or mathematics in a government or a private college.

OPTION:3
If you have age and means to support, then take up the GATE and do M.Tech computer science or mechatronics from a reputed institution that will enbale you for campus recruitment or a good job. You can also continue the part-time or evening tuitions.

You can go for some of top courses of computer software just like languages or CCNA or ethical hacks etc. and get certified from a good company or institute as its a highly demanded area. You can go for good coaching institute or colleges also.