Hello aspirant

Hope you are doing great there . I regret to say this but you have to submit your OBC - NCL certificate in JEE Advance registration form , only then you will be eligible to give JEE Advance and otherwise not . Also if you manage to get a good rank , and you qualify OBC - NCL cut off in jee advance , then also you have to show the certificate again .

Therefore the category certificate id neccessary .

I hope my answer helps

Wish you all the very best !