Hi,
You have mentioned that in the property papers your father's signature is there, but it is in your uncle's name, did your dad signed as a witness.
1. Since the property stands in the name of your uncle and if the sale deed shows only his name, you cannot legally make a claim of title and ownership.
2. You have the possession and the utility bills in your dad's name, what about house tax, is it in his name .
3. At present if your uncle is threatening to evict you, approach the court with a permanent injunction seeking against alienation of property and creating any third party rights.
4. Collect any documentary evidence to prove that your dad has invested the money, his source of income and at the same time your uncle was not having the source to purchase the same. However all these are mere attempts to hang on to the possession, your dad should have transferred the tile in his name, before the construction of the house.