Will or Convention Deed
Background: I am adopted from my Mamaji (i.e. the mother father which I am talking above are my buaji and fufaji). There is no adoption deed in place, however we have my MCD birth certificate, All my School certificates, all other docs incl passport wherein my buaji fufaji are shown as my mother father leading to no need of adoption deed. My buaji fufaji (i.e. my adopters) have 8 daughters.
My grandfather bought a property in 1963 which after his death automatically got transferred to My Dad(Adopter), Chacha and 2 Bua's (Adopter family). 1 of my Bua relinquished her share in favour of both the brothers and 1 Bua sued and us for her share. As a result we got the case settled by paying her an amount decided by District court as a matter of settlement in lieu of which my Bua relinquished her share also in favour of Two Brothers.
Since my father died, my father's share in the property got transferred to my mother as stipulated in my father's will.
Now, my buaji wants to transfer that property to me with surety that none of my 8 sisters can claim any share in that property. Seeking your opinion on what is best and non challengeable way: Will or Convention Deed or any other way.