Construction of amenities in terrace and building

I am planning to buy an apartment (Ground floor parking + 4 floor + Open Terrace) which is under construction. 1) Shortage of parking The builder claims that they are 80 parking available on the ground floor for 120 apartments. There is no space for open parking within the entire building. In the approval plan, it shows that there are 20 car parking and 60 two-wheeler parking. Question 1: Can the builder sell the parking on the ground floor? Many people say that parking on the ground floor is a common area and no one can claim ownership once the association is formed. If that is the case, who will happen to the 80 owners who brought parking slots while buying an apartment? 2) Amenities on the terrace: In the approval plan, the terrace is marked as an open terrace whereas the builder says all the amenities such a gym, community hall, mini theater, space for indoor games will be built on the terrace. Does this not come under violation? 3) Change in the floor plan In the approval design, they have windows in the master bedroom whereas they are constructing a balcony. Can changes like this need prior approval? Thanks