My father is being threatened

My mother and her family are threatening my father for money. Her family (mother and brother) are teaching her all the bad things and are barging in between my parent's relationship. Her family is even planning to file a domestic violence case which will be truly false. My father on the other hand is saying that if my mother wants to leave us then get divorced to which my mother is responding sourly because she'll lose all her authority on my father's assets. Her brother and mother are trying to make my father look bad and saying that my father mentally tortures her and they even badmouth and use abusive words to my father and all my family members. All these things started to happen because of what happened in april, 2019. My mother went to a mediation center in her hometown with the assistance of her family without telling anyone in my family. Though she says that it was not betrayal but she kept all this hidden from my family. My father was very stressed back then to because we couldn't reach out to her and when we did she blew it like it was not a big deal. My father sent a legal notice to her regarding all this and still accepted her and brang her home. But after a month her family filed a domestic violence case because they wanted revenge of the legal notice my father sent to them. My father had to visit police station but the police there understood that my mother's family specially her brother is barging in my parent's relationship. My uncle after that incident visited our home and started creating a scene. But in 2020 she demanded to go back to her hometown and never come back. She wanted my father to sent her home so as to make again make a false allegation of him sending her home forcefully. Till date she wants to go back but now she wants my father to send to her with all her streedhan (my father is not disapproval of this) and maintenance money. **My mother has always neglected me and my brother. She used to hit and abuse us. She barely does household chores. She badmouth her husband, kids and paternal mother. My father is the only one who looks after us and care about our wellbeing. To which my uncle said that we are bribed by our father and we are on his side. Please guide what can be done in order to save my father from all this.