Domestic violence by my father

My father used to beat my mother regularly but my mother used to bear everything for us and because of the society. But on the night of 3rd April he in the middle of a conversation beat her brutally. As i live far, i was informed about, by some of my friends the next day. I left immediately for home after this. Upon reaching there i found her lying on bed a little unconscious in pain. The wounds on her body were visible. After which i decided to leave to my maternal home without him even knowing. I lived for three days at my friends home and then left for maternal home. Now after reaching here he is mentally torturing us over phone by using vulgar languages and abuses. He says that i want my younger son back. it was you who took him there and now you will have to bring him here at any cost. But my brother does not want to go to him. And none of us actually want to go back to him. I reside in university campus and he is threatening to come there and create drama over there. In addition to this he is threatening that if you don’t bring him back either you or i shall die. In the hurry and such adverse situation I could not file an FIR neither do I have injury report. But I have some of the recordings and some witnesses who can testify the incident. Suggest a remedy. P.S. i don’t want him to enter the university premises.