Regarding Agriculture Land

Hi Team, My father currently uses 4 Acres of Agriculture land for farming purpose and pays a sum of 1.5 lakhs to my Aunt who is the Heir to the property. Note: Currently the property is on my Grandfather's Name and it was decided that he will hand over the 4 Acres to my Aunt after his death. (There's no Written Document for the same ) It was just discussed in the family meeting. There's no Formal Agreement or a bond signed by my father to pay 1.5 lakhs to my Aunt on a yearly basis . It was just discussed with Mouth. Now since past couple of years There is no proper Water and rains and My dad hasn't been able to pay the amount . He has regularly paid 1.5 Laks per year for the past 11 years until he faced losses due to non availability of water . My Aunt is threatening us that she will go to police and get my Dad Arrested. Last week she came and locked our house gate from outside and gave the key after 30 minutes. What legal steps can i take to keep my family safe ? Can police get involved in Land Disputes ? Please provide an answer Regards, Kaushik