Can Builder allot the carparking on their own whims and fancies

We selected a max sqft flats (B-Block) and bought at chennai . This flats is having 4 blocks , stilt +2 , total 22 flats Stilt is having car parking , multipurpose hall , office room and small gym room .Builder is two partners (they are relatives ) , we have booked thru one of the partner and during purchase he has confirmed that the carparking is available(we paid carparking charge also ) and allotment will be done later when they are finishing the sale as per buyers preference . we were 6th buyer in that flats .Now the other partner is marking the car parking allotment , he gives us diff parking space below some other block ( C) when we ask for the specific and he says that the marking is done below the respective flats .But one person in our B block is booked thru that partner has been given preference and for him it’s allotted as per his wish , i.e below A block . But for us below our flats multipurpose hall is there and space is been suggested below the other block (c ) , we have asked for the specific parking below the A – Block . Even as on date 2 flats not yet sold in A block and for the same also they are marking the space .Now Builder is going to prepare a carparking layout with the flat numbers . Now my question is 1. Who has the power to allot the car parking in the common area ? 2. Is there any procedure to mark the car parking space In the stilt ? 3. The reason said by the one of the partner of builder is valid ? or not. 4. Builder not yet handedover the common area . but he is making flat number marked car parking in paper.. is it correct 5. Can the builder alott the caprparking space as per their whims and fancies ?