Case against step mother and divorce between parents.

Hi I am 25 currently and all we, three siblings, are adults now, we lost our biological mother at a very young age (I was in 2nd grade), my Dad had a second Hindu marriage, my stepmother has been biased and never accepted us with true spirit, my parents keep having issues over the differences in her treatment towards us, for the whole time till we turned 18 and above we faced a lot of verbal and physical abuse from her end, we were not given the very basic human treatment expected from a mother, we thought after getting independent and earning our own living will make this less or stop, but she still keeps creating problems and does not let us live peacefully in our home, we have to cook and eat our own separate meals, and she often stops us from that and asks us to leave her house which is in my dad's name but she claims it's her as a wife and we get nothing. I have a video recording of her abuse against me and also there are two cases in her work place, she is a teacher at a school, with a decent salary, she has been transferred due to an abuse towards one of her students, who's parents raised a complaint to school authorities. What would be the best way to sort this out and stop her from treating us the way she is right now?