Property dispute related

Hello Sir, In our family, my great grandfather had 2 sons.My grandfather and a younger brother. My Grandfather has 3 daughters and a son. My Grandfather passed away last month and my grandmother passed away long time ago. We came to know that my uncle(only son of my grandfather) has executed a gift deed to transfer all the property(agricultural lands) to his name. And also did a patta name transfer. Out of these agricultural lands some are inherited from my great grandfather and some are bought by my grandfather. None of the family members know the details of the property earned by our great grandfather. In 1960's, my grandfather and his brother separated the property which includes their own earned property and the property of our great grandfather. Since we didn't know the property details earned by our great grandfather we contacted the revenue department to get the documents. But we got only the document of 1960 which my grandfather and his brother separated between themselves. 1)Now if my mother wants to claim the property Is there a chance ? 2) Since we are not able to find the ancestor property details can we claim a share of the property which my grandfather gifted to my uncle . 3) Is it possible to do the above even after the registration of land etc are done in my uncle's name.