On your father death his 50 per cent share would devolve on your mother , you and your sister

2) you and your sister can execute relinquishment or gift deed to relinquish or gift her one sixth share in favour of yiur mother

3) relinquishment or gift deed should be stamped and regd.

4) apply to society ti transfer father 50 per cent share in favour of mother . Enclose father death certificate relinquishment deed executed by sister and you

5) society will on execution of indemnity bond transfer the share

1. On death of your father his half sahre is equally devolved upon your mother, sister and yourself.

2. So if you want your mother to become half sahre owner then you and your sister will have to transfer your respective shares in the half sahre of your father by way of deed of gift.

2. The deed of gift can be executed and registered in local registration office which requires payment of stamp duty.

3. The society has no say in the inheritance and inter se transfer of shares among its members.

If and only if all the other legal heirs of your father i.e you and your siblings give a NC the share certificate can be transferred in your mother's name alone, failing which the share certificate has to be transferred to all his legal heirs i.e widow, mother and children. Apply for mutation to the society.