Legal car parking allotment

Hello, What is the legal document to prove an apartment owner was given a car parking space? We have a great confusion in our building As one of the apartment owners shows a receipt by the builder/owner and that he has bought it for 150000/- But, I read on the internet that and open car parking space without walls(closed) cannot be sold. Another owner shows the schedule B of the registration document which mentions " allthat The flat *** on second floor in the complex known as S***se Admeasuring 1250 sqft(including common areas and Car parking) along with UDS 21 sqyrds Out of the total land of 267 sqyrds on survey number** - this owner shows this schedule B and states that he has the right to get a car parking space. However this schedule B with brackets of car parking is exactly the same for every owner whether he has parking space or not. Lastly i have registration document which clearly mentions like this in the starting description of the property " whereas the vendors herein Have offered to sell the Flat *** on second floor, in the complex known as S***e admeasuring 1250 sqft along with UDS 21 sqyrds Along with one car parking" Please let us know who has the correct document for the ownership of car parking.