How to get linked documents of my father house site?

Hi, My grand father bought land for the construction of house in my village.But we have lost this registration document ,in fact we do not know whether my grand father made registration or not for the bout site.My father has got the part of the site from my father in law as hire right. My grand father has 3 sons,among them 2nd one is my father.Now my father has gave me as gift settlement of my father's part. Now I am looking to construct home for my father after demolish the old home.For this purpose I am looking to take loan from bank. Now bank is asking me the linked documents for the site which I am wishing to construct the home. I have the following documents: 1.Registration document from my father as gift to me 2.EC for the same sarvey number 3.Adangal for the same servey number All the 3 documents not act as linked documets? Now my father only live,my grand father expired long back. Could you please advice what will be the alternative for the same. Thanks&Regards, Chittibabu