Builder promised 10:90 plan but is now backtracking and asking us to bear interest

Hi everyone,

I'm currently facing a serious issue with a builder and would really appreciate any advice or if others have experienced something similar.

At the time of booking, we were clearly promised a 10:90 payment plan — meaning we pay 10% upfront, and the remaining 90% only after the Occupancy Certificate (OC) is issued.

We’ve already paid a booking amount of ₹2 lakh, and this 10:90 plan was communicated to us through verbal discussions and promotional materials. As per this plan, we were preparing to make the 10% payment as the next step.

However, just at that point, the builder started backtracking on the promised terms. They are now attempting to renegotiate the payment structure, and asking us to bear interest on it — which completely contradicts the original understanding.

This sudden shift has left us uncertain about our rights and next steps.

Has anyone faced a similar situation? What legal or practical options do we have in this case? Can we escalate this to RERA or any other authority?

Any guidance would be greatly appreciated.

Thanks in advance!