Hi, I don't think that Development rights and Gram Panchayat approvals are sufficient for buying under construction property. You may fall in difficulties if buy. Because there are multiple documents required for under construction property, in absence of any these documents, construction may stalled at any time.
Yes, a under construction property always attracts home buyers because it you have to pay lesser than the ready to move in properties. However, one cannot ignore that investing in an under-construction property is a risky affair. You might face delay in possession and if the project is stuck due to a certain issue, there might be a long legal battle to be fought.
So it is always advisable to ensure the ownership of the developers/seller by conducting the diligence over the property.
Documents required for under construction property are:- land record, land use type, certificate of commencement, building/ layout plan approval, master plan of the area, No objection certificate and the other clearances, booking form, allotment letter and builder buyer agreement. You can also take the help of a lawyer or expert to analyze the the agreements.