How do you deal with a troublesome landlord?

Dad had vacated a room. couldn't pay the electricity bill too. had visited the police station with landlord. The police officer said they can't take any legal actions against dad as it was during lockdown rather go for a settlement. The landlord owner died and his wife and their sons have the place. In 2022, the wife with her son came, forcefully entered the house and I was alone. They didn't leave the house till 11pm or something. Used abusive language towards us. Dad didn't show up as he was out for work. Now again they have shown up. The wife is a violent person, always speaking abusive language, same goes for her two sons. Last time, the elder son came to our house at 8am, forcefully made my dad write him a cheque (he didn't sign it plus the bank got recently closed) and told that he will again come. Is there anyway I can handle these people? Such people are capable of using illegal methods like killing and beating. How to tackle them?