Delayed possession of an apartment and Compensation

I booked an apartment in 2018, helmed by a very popular lock brand that also has several other business verticals, with real estate being one of them.

The possession was supposed to be in June 2023 but was only offered to us in March 2026.

Since then, I have been asking them to pay up the delay compensation we are owed according to their very own builder buyer agreement and the company is refusing to do so.

They are stating that Covid and GRAP4 caused the delays.

Another person from the same building has already filed a case against them in RERA for the same and won. He was eligible for compensation worth ₹23Lakhs.

However the company is saying that they didn’t give him any compensation and are fighting the RERA order, though they are unwilling to tell us more details so we can verify their claims.

From a few real estate agents in the area i have found out that they are offering amazon vouchers worth ₹1,00,000 as compensation to the buyers and in return asking them to never raise this issue again.

I am yet to pay a few lakhs for the pending possession amount and am worried that they might cancel my sale as they keep threatening to do so.

Is it possible that I take up possession and then file a case against them in RERA Or does taking possession mean I cannot file a lawsuit against them?