You need to find out what the actual situation is.
Is the title to property in your grandfather's name?
Is the title to property in your uncle's name?
Establish that first.
If the property is still in your grandfather's name, what needs to happen to vest it in your uncle's name? In simple terms, being named in a will is not enough to show ownership such as to pass it on to someone else.
Is it possible to have the property vested in you and what are the tax implications of that?
What are the values here? When did the grandparents die? What was the property worth then? What is the property worth now?
Don't put money into the property until the issues are resolved.
mf