Indian succession act Christains

This is a roman catholic Christian family. Husband died without a will. He had a flat in joint ownership with his wife in a cooperative society. His name first and wife's second. Now who gets the flat. He has his mother alive, wife, 1 major daughter. As per indian succession act is should be 2/3 to daughter and 1/3 to wife. However, the judge seems to take the issue as per class 1 legal heir applicable in case of hindu succession act when the lawyer was consulted. My question is is my stand right that only wife and daughter will inherit? Or will the mother also get any share? If the judge goes as per class 1 legal heirs in this case what is the solution? Also will the wife's 50% share also get distributed or remain hers?