Divorce-hindu who converted to musilm and married a muslim indian

5 yrs back. My sister during coollege days converted to islam and married a mumbai boy. she ended all ties with us and settled in Qatar. A year back she again contacted us bcos her father jnlaw tried to molest her even her husband regularly visits prostitutes....she want to come back and take divorce. but they are not allowing her to come....need legal advice...who is familar with sharia law of qatar...and who can help me bring back my sister.....i dont know who to contact and where to contact.