Child custodey

Hai Sir, I got married at Aryasamaj Mandir on my 23, I had married a Muslim girl and she converted to my Religion (Hindu) . Later few days her parents approached and told me the actual marriage will be conducted after her degree exam and take her back. But they tried to separate us. Later they applied to renew her passport and i came to know and i denied the issue of passport as they claimed there as Unmarried in application form. Then they approached the family court for getting the marriage null and void. But she had came along me at the court and we lived around 10 years very happily. Now we have 2 Kids,of 6 & 2 year old. Last year her parents again come for settlement and they tried to believe me that they dont have any other issues to me. Unfortunately i believed them too. But now they started to convert my Kids to their religion with the help of my wife. On an occassion when my kids school application form were filled by my Father in law when i was out station at that time he had filled the religion column as Muslim. I resisted their every movement and as a result i had lost my Wife too. Now she is living along her parents. My kids are staying with me too. Kindly advice me whether i will get my kids if i filed a petition as myself were cheated by my wife ,by converting once to my believes and living around 10 years ,and also need protection as her parents are forcefully doing some religion conversion to my Kids. Please give a reply at earliest.