Non allotment of parking place by builder

In our wing 12 flat are there there. Builder has allotted 12 parking. Out of which 10 parking allotted to my wing member and remaining two parking allotted to other wing members. He has not allotted parking for two members. There are two vacant places are available in my wing. I would like to ask you how to get the vacant place allotted to me and the member not allotted parking.Builder has already transfer his right to society. Please clarify the query.