Family Inheritance Property

Hi ;
I am trying to get some help I am over 40yrs old and my parents divorced when I was 10, I have 1 sister . My father died 17 years ago he had 2 other brothers one deceased prior to his death no wife or children, the other still living not in good health and has 3 children and a wife. My grandfather died several years prior to my fathers death but my grandmother died about 2 1/2 years ago in a nursing home and had alzheimers for about 3 years prior to her death. My uncle of ill health is the only one living on all the family property nothing has ever been said about taxes on the property or what would happen if he died or if we were suppose to help with taxes after my grandmother died etc...what should we do? we have never communicated with this uncle much only when there was a death in the family or something very short and casual.
Do my sister and I have claims to the property or is it to late.