Right in property

Greatgrand father (mothers grand father) died in 1960 Grand father (mothers father) - Alive & has 3 child (2sons & 1daughter - my mother) My Mother died in 2011 & has 2 child (1daughter 33 years & 1son myself 35 year) Query1: great grand father has self aquired property, after his death (without any will) property comes to grand father. Then grand father sold half property (without any NOC of my mother) in year 2010 and give money only his 2 sons not my mother.... Then tell me what is our right in balane property & that money. Query2: my grand father has self aquired property, he sold half of them in 2010 and same story money gives only his 2 sons not my mother.... Then tell me what is our right in balance property & that money. Query3: can any one sold property @ age of 80 or make a will (because he is not in condition to take any decision)