Hey Anupam

It is not a matter of concern that you were a student of which board in your 10+2 . You have to satisfy one of the following two criteria for JEE Advance

You should have passed 10+2 or equivalent examination with an aggregate of atleast 75% marks . For SC/ST and PwD candidate there is relaxation of 10% as they need the aggregate of minimum 65% marks 

You should be within the category wise top 20 percentile of successful candidates in their respective 12th standard  board. The score secured in following five subject will be considered for aggregate as per the second criteria

1. Physics

2. Chemistry

3. Mathematics

4. A language 

5. Any other optional subject with higher marks

All the best!

Hello Anupam,

No matter from whichever board you are from whether it is CBSE, ICSE, RBSE, UP, BIHAR or any else according to JEE Guidelines one must score an aggregate of 75% in respective boards in order to be eligible for the Examination of JEE. If you have not scored minimum percentage set by JEE then no matter whatever rank you get IN JEE you will become ineligible for the selection.