Hi Candidate! The first thing you have to do is to contact to your school. And then write a application to your principal and tell them about your problem. You may need to write a application to the chairman of the board under which you had given your exam i.e. (CBSE, ICSE).

You can also go to CBSE official site and get helpline number and contact them and ask them how to regenerate admit card .

Hope it works.

Thanks.