As per the new guidelines of JEE Advanced 2020 you need to upload a declaration in lieu of OBC-NCL certificate during registration if you don't have a fresh OBC - NCL certificate issued on or after April 1, 2020 . You have to upload the fresh certificate on or before 26 September, 2020, 5 PM.

If you can not renew your certificate within stipulated date, your registration will be cancelled. So, try your best to collect the certificate as soon as possible. Good luck.