Grandmother's Property was Sold by Grandfather. Is that Valid?
A Property of 0.25 acre, was purchased in the name of my Grandmother in 1956 in Tamilnadu. The same was divided into 4 portions and sold to three different parties out of which two portions to two parties (1&2) in 1987 and two portions to one party(3) in 1987 and his wife in 1988. We do not have any of the documents. Recently i got the copy of documents from the respective Sub Registrar Office. When I validated the documents, I found that the Sale of Agreement for the portions sold to Party-1, Party-2 and Party-3 bearing the Thumb impression of my grandmother, wherein the portion sold to Party-3's wife bearing the signature of my grandfather. Now my question is
1. Whether the particular Sale of Agreement bearing my grandfather's signature is valid or not?
2. Can I plead for the this Sale of Agreement as Void?
3. If the Sale of agreement is Void, then What are the possibilities that I could claim rights on the property?
4. Any other key points where I can fight for it.
Please help me on this Case.