Hey

The SEBC  is a state level reservation provided to students and is not applicable for Central Reservations. But centrally I think you will fall under OBC category as both the categories are linked. For mare clarification you can contact the CAT helpline numbers or else kindly contact your city local body issuing the reservation certificate and get it clear from them whether they issue different OBC certificate applicable for central reservation or the SEBC certificate is the only OBC CERTIFICATE.

For your reference I have attached the link of the official website of CAT below,

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

Hope that helps.

Thank you.