He'll Stephen

christiancan claim OBC and Scheduled tribe reservation . So their is no need of caste certificate .

Only followers of Dharmic religion can claim Scheduled caste reservation

If you belong to scheduled caste category and after conversion to Christianity you legally changed your name ( from Hindu to Christian name ) you can't claim Scheduled caste reservation . If you don't change your name then you don't need caste certificate yours old caste certificate is enough to claim Scheduled caste reservation . Nobody ask your religion.

Best of luck..