This is my advise to you:
1. The builder will hand over to you an Allotment Letter or the Offer Letter;
2. Read the terms and conditions of the Allotment Letter;
3. If you feel there is legal obligation on you to fulfill or not avail the refund of your deposits etc. then don't go ahead with it;
4. Since it is MahaRERA monitored you have nothing to worry about;
5. If the project gets cancelled and the builder does not refund to you, you can sue him.