Property possession- can property be claimed

We have been living in this house for 15+ years nw. The property was in my grandmothers name. She passed away few years back and gave the rights to my fathers sister. She never lived in this house since 2005. My father has taken the NOC of the rest of his siblings but not of that sister and their sister in law(fathers elder brothers wife) my mother passed away a few years ago and now my father is also not so well. Do we get the right to keep the property fully in case we have bad news about dad