Parking issue with builder

Hi, I purchased a new house in Aug 2018 and started living there after registration done at the same time. I got the NOC letter from builder but he is not providing the possession letter because of parking issue. In my index 2 it's clearly mentioned for covered parking but when I asked for possession letter, builder is saying that either pay money for covered parking or change the index 2 that I've purchased house without covered parking. Please suggest, what to do further. Thanks, Raj