Dear Brother,
It is observed by Hon'ble High Court of Mumbai, in one of the Judgement:
Ramagauri Keshvlal Virani vs Walkeshwar Triveni Co-Operative Housing Society
Ltd. & Others decided on 5/7/1999
https://indiankanoon.org/doc/122497/
" 11. In fact none of the provisions individually or collectively authorise the builder to sell a terrace of the building. The words such as common areas, facilities, carpet area do not include "the terrace" and therefore none of the aforesaid provisions can be interpreted to mean that a builder or promoter can dispose of the terrace to one of the purchaser of flat.
12. It is therefore clear that there is no statutory provision authorising a builder to sell terrace to the petitioner........"