Advise him

You must follow the prodedure given below to correct your DOB.

1. For getting the date of birth changed in your date of birth certificate first you have to prove your correct date of birth by showing supporting documents like mark sheet of 10th or any other relevant document subject to the satisfaction of authority going to order change in you date of birth certificate.

2. After arranging the proof of your correct date of birth you have two options as follows:

i. Visit your local municipality and discuss the matter with the concerned person. Go through the procedure informed by him and file an application for getting the date of birth changed in your date of birth certificate.
ii. Alternatively file a civil suit in the Court of your Jurisdiction. In this civil suit submit all relevant proof of your date of birth and prove that the date of birth on the date of birth certificate is incorrect and seek directions from the court to the concerned authorities (usually local municipal in most of the states) to correct the date of birth on your date of birth certificate and issue a fresh date of birth certificate to you.

3. You may find it a bit difficult to handle the above procedure if your previous experience to handle local Government is nil. In that case I would suggest you to take the help of someone who knows how to deal with these things and people. You may also get in touch with local advocate to get the things done quickly for a reasonable fee.

I hope the above suggestion would be of some  help.