Hey there!
To avoid any ambiguity you should provide caste certificate only in the format described by JoSAA. You can find the format easily, just make a google search. It depends on the colleges you are applying in whether your hindi language certificate will be accepted or not, what if you apply in a state where they don't understand it? There could be a problem in some colleges, and some may be fine with it. Therefore if you could get it done in the prescribed format then do it.

Also to get the better idea of colleges you can get into, you can use the NEET college predictor tool, here's the link for that - https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer