According to the UPSC eligibility criteria “ a candidate will be eligible to get the benefit of community reservation only in case the particular cast to which the candidate belongs is included in the list of reserved community issued by the central government ”

So if your cast is listed in the central OBC list then you must get a OBC NCL certificate .

But if your OBC certificate has been issued after 1 April 2021 then then there will be no issue with that .

Hope you find this useful.