can i file a complaint on behalf of my sister

Sir/madam My query is regarding my sister She is continuously facing mental and physical harassment at the hands of her husband since her marriage in 2013 December only to meet his and his family members 'demand for dowry.When they realized they won't be getting anything more(as my parents had already provided more than their stature) they beat my sister and turned her out of the house and then they started harassing my family members and giving life threats to my old aged Father and my brother and also defaming other family members. Now they have started attacking the professional lives of other family members and mentally harassing sister is amafraid of filing any police complaint as she has been threatened with life threats in case she does so.I want to know if I can file any complaint on her behalf with national commission of women or any other body as now they are targetting life and profession of my another sister who is a government employee.we are unable to find out any suitable solution. Please guide. Thanks with regards Soniya bansal.