Parking spaces in cooperative housing society in mumbai

I have purchased a flat in a redevelopment society and the registration has been done before RERA came into effect. At present the society has been formed and we are having issues for parking spaces. The problem is due to the reasons mentioned below : 1) the builder has mentioned in the agreement of the old society members that the 1st and 2nd floor parking slots have been allocated to them in perpetuity/permanently. 2) The builder has allocated parking slots to all new flat buyers in their possession letters. The problem is that there are 30 old members and 24 new members and the old members are insisting that the parking slots on 1st and 2nd floor permanently belong to the old members and the new members will not be allocated the parking in these areas at any point of time. Also the old members are insisting that the allotment of slots done in the possession letters issued to the new members is not valid/does not have any legal standing and the parking slots in the stilt area are property of the society and will be reissued/allocated by the managing committee as per their will. The above stand of the old members is creating issues. My query is as below : 1) Can a property developer/builder permanently assign parking slots/parking areas to old members by mentioning the same in their agreements. 2) what is the legal standing of the fact that property developer/builder has allocated parking slots to the new members in their possession letters and what are the legal options of the new members if the old member are u=not willing to listen/cooperate/resolve the issue.