1. The GPA and the Development agreement if registered on payment of requisite stamp duty then there is no problem at least on this count.
2. Do note that no proper advice on title of a property can be given without checking the relevant deeds of a proeprty.
3. Hence I would advise you to show all the papers to a lawyer and then proceed to buy the same on his advice.
4.if any doubt arises then we may advise further.
5. However a typical checklist is provided below-
Title Deed (in the name of the seller)
Prior Title Deeds (of last 15 years)
Latest Tax Receipts (land and building if any)
Updated Encumbrance Certificate (covering last 15 years)
Building permit / Notice Of Commencement (from corporation, municipality or panchayat, if you are purchasing a house / apartment)
These are the basic documents required for checking the legal entanglements pertaining to the land. After going through the documents, if there are any complications, the advocate may call for additional documents if any clarifications required.