Hey,

If you fall in NC- OBC category you can fill the form In CAT with the same category and in place of the certificate kindly download the self declaration form from the CAT official website,

https://iimcat.ac.in/per/g01/pub/756/ASM/WebPortal/1/index.html?756@@1@@1

Fill that form and submit it in place of the certificate and do that only if you are sure that you will be capable to present the NC- OBC certificate at the time of Counseling. As failing to do so might cause you trouble.

You can contact the CAT authorities for further assistance.

All the best.

Thank you.