Property rights for property in rural area (village in UP)

Hi Sir/Madam, I wanted to seek some assistance in regards to a property issue in a village in UP (in case law varies from state to state). The issue is that my father many years ago constructed a house in his village, for which registration was done ....as in the process of title etc.. He gave his that house to his father, brother and their kids to live in. His father meaning my grand dad and his brother-my uncle and his wife have passed away many years ago. My uncle has 4 kids, one of whom has always stayed with us at our place ...can say, was adopted by my dad due to my uncle not being financially stable but the other 3 are now trying to claim property to be theirs..on the fact that electricity bills were in their fathers name etc..and no other proof. Someome from the village advised to take the matter to panchayat as every one knows the truth and the other party's mischievous behaviour. But I wanted to know what legal actions can we take as per law..and what evidences can we use ..moving forward so that we are prepared...and if the other party has any rights...and how can we dispute it. They have been living there for about 20 ish years and now showing their true colours.I really hope if some one can put some light on our rights.please please...please.