Keeping Adult Daughter At Home Against Her Will

I have an adult friend whose family tricked her into calling her back from her college to home because they do not approve of the guy she wants to be with. They took away all her modes of communication, drugged her, assaulted her, etc. It has been almost two years since the incident. She contacts two or three of her friends whenever she gets a chance to but she has to be very careful. She is concerned that she'll not be allowed to leave home ever or be forced to get married. She was a student of Delhi University. Now she's pursuing English Hons. From IGNOU. She is doing various internships from home and is very hard working. What can she do to ensure that if her family tries any of the assaults in the future, she can get help? Can she write a letter and sign it and ask her friends to seek help on her part. Who can she address the letter to and what are the components required. She just wants to make sure that her future isn't in jeopardy or she won't find herself helpless like before