Complaint to RERA for an unjustified commission fee of property purchase

I wanted to buy a ready-made apartment as a resale, where the agent asked me for his 2% commission plus 1.5% SALES PROGRESSION FEE as his company`s different department is taking care of the smooth transaction.

Btw, I never heard for this fee and I am buying the property for cash and not a mortgage.

Obviously, the agent wants to make more money on the transaction by adding some non-sense fees that should have been included in the commission.

Is there any way to complain to RERA?