Car Parking Allotment and refusal by society after formation.

Sir, I have purchased a flat in my area. There are 12 buildings of g+7 floor. Builder has already started giving possession to all flat owners. Before that, builder has called me to purchase a stilt parking for Rs. 3.5lacs. I refused to purchase the same. Some flat owners took the stilt parking by paying the builder cash amount. The builder will provide the parking allotment letter to car park purchaser indicating it is free allotment; also he is signing the NO OBJECTION UNDERTAKING from the flat owners who did not purchased the car parking. After few days, he signed me to society formation documents. He also took me in 10member promoter list of society formation. I have few questions regarding the above said incident…. 1. Can the new formatted Society refuse the car park allotment, though builder is telling in allotment letter as free car park? 2. If Yes what will be procedure from society end? 3. If Society accept the car park allotment, what will be my role as Society member. 4. How can I use my position of Society Promoter in case of point no. 3? 5. My aim is to take free stilt parking, how can I get the same? Please answer the above questions. Regards, Navid.