What can I do if I was physically abused by my boyfriend?

Sir/Mam, Upon last week,my sister has been physically abuse by her boyfriend in the night at the empty street,she have serious injuries leave behind by him which includes small bones in her neck been broken,right eye completely shut and swollen and her right eardrum not functioning due to the beating and sign mark of strangleing mark on her neck. We told him to come out of his house several times and didn't oblige to it and shed a fake cry upon us,I keep asking him to come out of his house but he didn't want to,as i couldn't hold my anger anymore i puch him with 6 combos(not in his face) on the body and with a lil bit of Achillies heel hook on his left heel and stop it. We file a FIR on me but the perpetual case a file on me for the domestic violence in his house. What will i do in this situation? Please help!