Family Issue

My father has one elder and younger brother. My father taking care of them from the beginning and without even caring about his own family (my mother and myself). Now his brothers thinking to separate my father from my mother. If he is with them they can get all his money. my father is also cheating us. His main motto to bring up his brother's family and he doesn't need us. So he left us. Always it happens, my mom and me go and convince him to come to the home. He is working in the police department so he showing all his power to us. giving mental torture. In this LOCKDOWN period, he left us. Taken my car with him and locked the desktop. We are asking him to give those and telling him to provide all Bill payment, insurance, bank details credentials so that we don't depend on him further. my mother and I decided if he wants to go let him go. But he needs to give all house related details but he is not giving those. what can I do to get all these details?