Legal action against rapist?

My friend (now 24) was raped by her cousin since she was a 10 years old. Accused is 9 years older to her. He has sexually, physically and mentally harassed her and thinks of her as his property. He has cut her with knife, hit her with iron rods. She does not even remember how cut marks got onto her thighs. He is married and is a Indian army officer. No complain has been registered till date. Victim is terrified of him and is unable to do anything. He has also physically assaulted her male friends who were close to her. He has physically harmed her when she tried to resist and have also given her drugs in past to make her unconscious and has threatened her of giving her aids injection. He comes to her city once in a year and harms her and goes away. She has been totally destroyed and have attempted suicide twice. He has not done anything for past 8 months. Since he is everyone's favorite, it's hard for her to tell it to anyone as no one will believe her. She is afraid to take action against him. She is in no position help herself. My question to everyone is. 1. Is there any why she can file complain based on what has happened to her in past 15 years? 2. What are the ways of safeguarding her after the complain has been filed? 3. If the accused is punished, how to make sure he does not trouble her again in life? 4. Will she be able to prove everything that has happened to her? 5. How can the accused be given the highest degree of punishment? 6. How can she be kept safe? Thanks in advance.