In India, reservation benefits are primarily based on caste, not religion. Since you belong to the SC category, you are eligible for fee exemption based on your caste status, not your Buddhist religion.if you have minority certificate then only you are eligible for fee exemption otherwise select the fee exemption option as NO because it could lead to complications during document verification.

Moreover,it is necessary to check the specific instructions provided on the RRB application form to ensure you are filling it out correctly.

Hope it helps!!