Purchase of Patta land

Hello Sir, Thank you very much for your response, in further to my query i just came to know that the former got that land from his father and grand father. But there is no documents saying the land is given to x person and then to y and then to this former. how can i get that complete detailed history of that land. At present the former is having Pattadar Passbook, Ownership passbook and Adungal on his name. and in any of these book his father or his grand father names are not mentioned. Mean while i tried to get the Encumbrance Certificate on the survey number. EC shows since 2007 there is no sale happend to this land, but the land owner name is shown as a next to someone land. does the former has the right to sell a part of his land ? in this scenario is this land becomes a ancestral property ? if the former wants to sell a part of his land does all his legal heir's need to do signature ? if i want to get registration history of this land how do get it and from where do i get it ? once again this Land is in a small village in Andhra Pradesh near to Vijayawada. Thanks a lot in advance to all helping me in my queries. Surendra