How can i help my gradmother optain legal rights to property that was her parents and she is the only living child

It's hard to know without knowing if grandma's parents had a will or trust. Let's assume they did not since the majority of people do not. If that's the case then the heirs at law would be established when the second of her parents died. Let's assume at that time she was alive and she had two siblings who had died leaving kids. The estate would thus be divided into thirds and those kids would have a right to their deceased parent's share. Of course this is all a hypothetical guess. Your grandma would have priority to be the administrator of the estate and thus she should file for probate now. She could then sell the house. The proceeds would be splits in thirds, in my hypothetical, at the conclusion of probate. It could get more complicated if one of grandma's siblings were alive at the second death of the parents as then the child's spouse could also have an interest. However, let's not go there now. I would start by having grandma file for probate! It's important that she starts the probate as she has priority to be administrator. Good luck.