Hey,
I have read your query and would like to answer it. A power of attorney is a legal document that allows an individual to give authority to another individual to act on his behalf. The person who assigns the authority is referred to as the ‘Principal’ or the ‘Donor’ and the person who has been assigned as the authority is the ‘Agent’ or the ‘Donee’.
Now, upon the death of the principal the agent's authority under a power of attorney ends automatically. This is because a POA is designed to give the agent authority to act on behalf of a living person. Once the principal is deceased, they can no longer make decisions or take actions unless the POA document itself must explicitly state that it is durable and continues to be valid after the principal's death.
Assuming that the POA is not durable, now if the principal has written a will, then it will be executed by carrying out the demands of the principal by the person assigned as executor.
In your case since your mother has relinquished 50% share to you through release deed which makes it is your separate share in the property and you are the sole owner of it. Now, the rest of the 50% is still undivided, therefore, in order to sell the property, certain steps need to be followed, firstly, if there is any will written by your mother then it needs to be executed, Secondly, if your mother has died intestate then the rest of the remaining 50% property needs to be devolved by way of succession. Section 13(1) of Hindu Succession Act, 1956 provides general rules of succession in the case of female Hindu as:
A) Firstly, Upon the children and husband of the deceased.
You can, obtain succession certificate from the court. This document establishes you and any other legal heirs (daughters or husband) as the legal inheritors of your mother's property, it will specify that every legal heir will get one share each. All the legal heirs can now sell the property jointly with written consent or if there is no consent then there is an option of partition of the property.
If you are the only surviving legal heir then you can inherit the remaining property by way of succession, which will give you the absolute right over the property and its status will be as your self-acquired or separate property.
Hope this helps you with your query.
Regards
Parth Chawla