DTCP approved plan violated by the state.

DTCP Approved plan - Violation?!: Through a DTCP approved plan, our builder has planned to build 50+ apartments. We have booked an apartment of type 2BHK+1 Study room, based on their given floor plan. But while we verify the DTCP approval, we found that our booked apartment has been mentioned as 2BHK leaving the Study room as an extended living room.

My builder is saying that they could facilitate the study room in place despite it is not in DTCP plan. (1) Is it not violation of DTCP approval? (2) Will it bring any legal problem in future (post purchase)? (3) As per construction agreement (along UDS registration) which plan need to be highlighted to ensure the committed apartment delivery from the builder.