It is always advisable to have a thorough meeting with the owner or the title holder of the property. Sometimes it happens that the original owners is already died and the property is being purchased or sold through middlemen.
Following is the tentative list of Legal documents :-
1. The property card or title certificate.
2. The title deed or the mother document
3. The tax paid receipts
4. The plan of the property or the blue print
5. The society membership documents or share certificate
6. Previous loan related documents or statement
7. Commencement letter issued to the builder
8. Completion certificate issued to the builder
9. Possession receipt