1)it is necessary to go through the property papers to advise .
2)it appears that some properties were purchased in name of great grandfather and grand mother . on their death property devolved on your grandfather and his brothers and your father and his cousins . you have not mentioned when your great grand father died .
3)prior to 1956 property standing in name of great grand father would be ancestral in hands of your grandfather and father . if property was not subdivided and no partition had taken place how was property sold by your cousin grand father ?
The property inherited by a person from his father is ancestral in his hands. He is not the owner of the property, he is entitled merely to hold and manage the property as the head of the family for and on behalf of the family. The ownership of the property is in the joint family consisting of himself and his sons.As a result of the co ownership the possession and enjoyment of the property is common. Hence the coparceners cannot alienate the
property except for necessity without concurrence of all coparceners
4) on your grand father death his interest in property would have devolved on all his legal heirs including his daughters
5)as on date mutation has been done in your father name in property . if your uncle has filed suit for partition you have to fight suit on merits . it is necessary to go through averments made in suit and reliefs claimed to advise .