See as you have a OBC certificate and if you have lost then you can issue a duplicate copy of your certificate from the Minority and Backward class development department of your District Magistrate office. If you go there and ask the officials they will give you all the information about it and will provide you the procedures of getting this duplicate certificate.

Now if you apply and if you don't get the physical copy of the duplicate certificate then I would say you can get the print attested by DM/SDO/BDO written that you are a bonafide holder of this certificate and its original and verified. If you have this you will expectedly have no problems, but I would say it would be better for you to get the duplicate certificate out from DM's office.

I hope this answer helps. All the very best for your future endeavors!