How to correct my error in name?

It will cause a problem at the time of document verification. You may have to inform them and they may give you some time for getting it corrected but they will allow you to join. After that within the given time, you have to get the corrected certificate.
Why when there is a mistake you have not got it corrected. Now based on your 10th certificate you can apply to CBSE and University to get the name corrected.
You contact the school in which you have studied your 12th class. Tell them the problem and apply in writing for the name change. You have to attach an attested certificate of your 10th certificate with your application and pay the required fee. They will send it to CBSE and get the name corrected. They will correct the certificate and send it to the school. There will not be any problem even though you passed the exam in 2014.
Similarly, you have to apply to the university through the college you have studied for the change of name. The college will forward your application to the university. You can follow up with the university administrative office and get the name corrected.

Any mismatch in the name is a problem and source of inconvenience at the time of document verification which generally takes place at the time of interview or counselling sessions.

You can try to get these corrections from your education board office and university office by paying the requisite fee and submitting application along with the supporting documents where your name is correctly reflecting.

If this is not feasible then you have to contact a lawyer and get an affidavit prepared in the matter giving the details of these mismatches and correct situation at present. The affidavit should be countersigned by a first class magistrate. You can keep a copy of this affidavit with you and show it at the time of interview or counselling so that your correct name can be taken in cognisance by those 'would be employers' for you.

A. Is there any problem in taking job in Infosys or any other company and what should I do now?

You name is a mismatch in your 12th and B TEch.
Yes, there would be problem for the MNCs or any major organisation for that matter. It can be rectified.

B.It is too late so I can't get it changed from CBSE. I have passed 12th in 2014?

You still can do it. There is one factor, the rule 69.1(ii) that states that the application for change should be done within one year of declaration of the result.This was amended to allow candidates a five year period from the date of declaration of the results to seek any changes. lease check with the authorities.

The procedure for CBSE is DIFFERENT from state board.

This site gives you the forms, guidance notes and the address of the offices (http://cbse.nic.in/newsite/forms.html)

The charges for this service is around Rs 1000.00 in 2016

You also need an attested copy of the school admission form, attested copy of the admission register sheet that has your name, copy of TC, Marks certificate, Pass certificate and migration certificate if you have used.

You will need a name correction afiidavit, this can be procured via the Notary in your region/ civil courts. Once this is done, please publish your name change/correct name in two newspapers (one English and one vernacular).

C. For the degree certificate.

Please check the university under which your college comes under. Then visit the website, many universities do offer online submission for such services provided you have the necessary documents and pay the prescribed fees. You can also send the papers to the appropriate person at the registered university office for the name correction and please keep all the correspondence carefully to quote in case there is a delay etc.

Image credit: CBSE site

Any mismatch in the name has to be corrected immediately so that it may not create any impediment in your career. Assuming that your name appearing in the class ten is correct, and the names appearing in class twelve and B.Tech are not matching with that of class ten suggest that this point needs immediate attention so that the future complication can be averted by changing the mistakes crept in against your name.
You will have to write an application to the chairman of the CBSE Board indicating the error involved in your name. The application must contain the remark of the Principal of your school suggesting the the correction of your name. He may verify the admission register to see if mismatch originated at this stage. Along with this application, enclose the attested copies of your class ten certificate, your Aadhar - card, Voter ID card etc in support of the proof your correct name.
Similarly, the same process needs to repeated for the correction in the B.Tech certificate where the Principal of the Engineering college would put his remark regarding the mistake and requesting the vice - chancellor for the subsequent correction to made. You will have to enclose the attested copies of Aadhar - card, Voter - I'd card etc apart from photocopy of class ten certificate.
The other way would be to approach a lawyer for the affidavit - purpose and he would produce all the necessary documents required for this purpose before the Notary - magistrate so as to get an affidavit. On the basis of this affidavit, get it published in a leading English News - paper apart from a local one. Retain the cuttings so that you may show them in the process of verification whenever it is required.

Name,father's name,Date of birth are the basic details which required till our last breath for anything to be proved and they should be similar and a correct one in all documents. The school certificate for seniors and birth certificates for youngsters become a valid one. As the date of birth is deciding matters in one's life till his end,much care should be taken in the beginning itself. School certificate,college certificates,aadhaar,Pan card,voter Id, driving license should tally each other. You immediately approach in person to the college authorities and get corrected. No correspondences will yield good result rather than personal approach. Your delay will make the matter more delay.