Can parking space be allotted by builder

Builder has completed the building in the year 2013 and subsequently all 25 flats were occupied. Builder has sold all 25 flats in the year 2010-12. There are only 23 car parking possible inside under slit area. Builder has marked 2 car parking out side but within the building boundary wall. He has also informed that he will make shed for this. Subsequently no progress was made in this issue. People are keeping Cars and bikes in different places inside without allotment. We want to know whether Flat owners / Association can decide the car parking allotment. Whether it should be Registration seniority basis or lottery. If it is a Registration seniority basis, whether 1st Flat owner ( Original Buyer from Builder) or 2nd flat owner ( Person purchase from Original buyer) registration seniority will be considered since around five flat are sold again by Original buyer.