Learning of which subjects would help seeking a job?

Learning has no limit of age etc. But you would have select your course in the beginning with some aspiration. As you have finished your B.Tech it is highly advisable to avail a job immediately and raise your practical experience and if you want you can add on many degrees of your interest to any level.

There are many add on courses which can be taken up after completion of the engineering degree. These courses will help an individual to get the job in those specialised areas.

One thing which is important at this juncture is to identify your interest and aptitude and accordingly select a course. One can always excel in the field of one's liking. There are many options for these courses. Certificate and diploma courses in computer and software area is a good option. You can think of doing that in System Management, Repair and Maintenance, Database Management, Networking and System Analysis etc.

If you are inclined towards financial and managerial line then you can think of going for courses in Finance and Accounts, Office Management and Automation, Basic Financial Management etc.

There are many other streams which may appear to you away from your core area but they deserve mention as they have potential from job point of view. Environmental Science, Safety and Security, Handicraft and modern garments, Insurance, Archive Management, Instructional Designing, Chemo Informatics, Retail Management etc.

Another important thing is do not shy away from a small job having small renumeration. The reason is quite simple that it may be a small job but it will provide you a quick experience in less time and that will go a long way to help you to switch your job to greener pastures.

So do not feel discouraged and demotivated. Today the job position in our country is really very tight and competitive and one has to do a lot of hard work and efforts to carve out a career.

After there are many ways to start your career. But what is your specialisation in B Tech you have not mentioned? If that is known we can guide you in a better way.
Anyhow if you are a computer science graduate you try to do some additional certification courses like do net or cloud technology courses. That will give you an additional edge for getting a job.
If you are a B.Tech in other engineering subjects also the above-said courses will be useful for getting a job.
You can attend GATE examination after getting your degree and if you get a good score in that, you will get a seat in M Tech with scholarship which will take care of all your expenses. With good GATE score, you will get government jobs also R&D and manufacturing organisation.
You can also try to go for MBA from a good institute which will give you a better chance of getting a job in a good organisation.
Another area you can think of B.Ed. This will give you a chance to get a teaching job in government schools
These are all the where you will think of getting a job.
The important aspect is the concentration you will put and the hard work you carry out in a particular field to have a good chance to get a decent job.

Your qualification will pay you dividend if you revise your course periodically especially when you are are likely to face some interview connected with the IT jobs. The employer would assess your strength with the varied questions including your updating in the stream you have acquired.
In nut shell, you should have the skill of creating impact with your ansewers and this can be achieved with your presence of mind. Be prepared for the latest inventions in your stream. You may be asked such questions and apart from it, you must be familiar with latest developments of news both international and external one.
Your presentation of the facts will lead you to sucess.
You can also clear GATE so that you can ultimately initiate M.Tech course.
If interested for the management course, you should take up the same with a reputed institute like IMM or any reputed B - schools.
You may look out for probationary officers examinations of different banks and by having cleared the written and oral test, you can join the officers cadre in Banking.
Options are numerous, you have to act accordingly.

opt for a management degree with a reputed institution

Now a days most of the organisations are turning to online digital modes for their record keeping and office processes. In this respect any course in Database/ Oracle/ SAP and other general office automation will be useful as such vacancies will be coming up time to time and one can apply for that.

Your engineering background will make you eligible for specific assignment in the same organisation also once they come to know your core strengths.

It's better to do some certification course in the subject you are interested in. As you didn't mention the stream from which you completed your engineering so I assume you did computer engineering. So you have lots of options in the market. Here are a few options:

Data Science for Digital Marketing
AI in Finance
Numerical Control Course
App design with Swift programming
Microsoft Professional Program in DevOps
Microsoft Excel
Course in Predictive Analytics
Python Certification
Online Software Courses
Computer Security
SQL Query Language
C++ Programming Course etc

Apart from these course you may search on internet too.

Also if you have an interest you may go for MBA and GATE after completion of your engineering.

Since you have not mentioned your area of interest, I will advise based on your JAVA course and general job market trend. If you want to make a career in to IT sector then joining a course for C++, Python, SAS, SQL is advisable as these fields are having good job demand in the industry and you can be job ready in 4, 5 months. One more course which is going to create a lot of jobs is AI(Artificial intelligence) and ML(Machine learning). You can opt for an institute based on your budget as there are many colleges and institutes providing these courses. It is advised to get some entry level job even it pays less because it will help you financially and you can sponsor your studies yourself. You can do these courses in weekend mode also as many of the institutes provide the course in weekend mode for the working professionals.

Today, the companies are looking for candidates who have managerial skills in the same field. With every basic degree of Education, like engineering, having an equivalent degree in managerial course have become a norm, though, in the employment advertisements, there might not be a mention on this requirement. But companies do pick those candidates who have done an MBA course on their respective fields.

Moreover, I would suggest you to look for job advertisements online, with the search criteria describing your qualification. The search results will come up with advertisements, that will have their own declared requirements. take note on the additional qualification they are asking for. This will give you an idea to take up a study further that will help you get a job of your choice.