Legal advice to take my sister out of harassment from her husband

My sister is in deep trouble. She is not free to talk to father, mother and sisters. She is not free to meet/call us from past 2.5 years.she has no food to eat past from 3 days. Her husband beats her red and blue. Financially she is not strong to take her decision by own. But due to some strong threat by her husband she has lost control of herself and forced to do whatever her husband wants her to do. Her husband said to my father and mother if she visits there place she will kill her. After so much torture she has gone to her parents and currently staying with them. When her husband got to know he created a ruckus in front of my parents. Then they went and complaint to police station near to our house on 14th march but no response from police please suggest me the steps to be taken i want her to come out of this harassment. She deserve her dignity back. Kindly suggest legal way to take her out of this. Please help she is not in a state to help herself and she has a daughter of 2.5 years Her life is worst then animals. Her husband has full control of her