Legal heirs of grand father

Dear expert lawyers My name is RK Reddy from Hyderabad I would like to purchase a land we took pahanies from 1954 to as on date. The seller grandfather name appears from 1954 to 1989 as per ROR 1993 his grand son name transferred got proceedings. His grandfather died 1985. Grandfather had 3 sons but he has given the land to two grandsons total extent 11 acres 1 person got 6.20 hunts 2 grandson got 4.20 hunts 2 nd grand son willing to sale the land. Now the query is his grandfather (ILLARIKAM)Lterally means bridegroom goes to the bride family and lives permanently with them. Purchased the before 1954 records states him up to 1989. Can we purchase this land if who all legal heirs to be attend for registration