Dear Student,

This is the internal matter of college, you can talk to the college administration that you would submit the caste certificate after the gap of mont, there is good chance that they allow you and give you some time to submit the document.

And for the fee you can talk to the college management that you will pay the fee in the installment here also a good chance that they will allow to pay the fee in 2-4 installment (depends upon the college).

And don't forget to write the application for that purpose and take the sign on that application of the college administration.

Good Luck :)