Hi

In Maharashtra MBA CAP registration process step 2 will be verification of documents and according to their official website

"The SC, ST, VJ/DT- NT(A), NT(B), NT(C), NT(D), OBC, SBC and EWS Candidates who submitted receipt of Caste/Tribe Validity Certificate, Non-Creamy Layer Certificate, EWS Certificate during the E- document verification and confirmation period should scan and submit Caste/Tribe Validity Certificate, Non-Creamy Layer Certificate, EWS Certificate on or before last date of Reporting of Final CAP Round II, otherwise these candidates shall be considered as Open category candidates."

As far as I know it won't be a problem changing from a caste category to general category though vice versa it's not allowed.

The other point is if the registration would be fresh meaning they will ask for all the personal details again then in that case you can fill as general category. If it's not the case then don't upload the caste document in the verification step you will automatically be considered as an open candidate.

hope this clarifies!