How to get getshare from my father and his share to

We are 2 sons and 2 daughters to our parents. My father inherited some agricultural land and acquired some agricultural land during his tenure. My brother requested his share in 1998 and my father shared property into 3 equal parts and mentioned his share after his tenure to go equally to both of us. Now my Father age is 75. During sharing just we wrote on plain paper and devided accordingly with 3 of our signatures and my brother got a patta pass book for his share and he does't have children. Now remaining my share and my father share is on my father's name only ( means he have patta ass book for both of our shares) Now I want to take my share on my name as a gift deed or through pass book. Also my father's share will to be registered on my son's name. My sisters are dmarried in april 1989. what documents are to required to get my share on my name and my father's share on my son name. Is there any rights for my sister's and brother to claim share in future. If I get it register my father's share on my son name remaining 3 to be signed on that document or any will is enough. Pls advise. Thanks n regards