In India, the laws related to child custody are governed by the Guardian and Wards Act, 1890, and the Hindu Minority and Guardianship Act, 1956 (applicable to Hindus). Under these laws, the welfare and best interests of the child are the primary consideration while deciding custody. In case the mother wants custody of the child from the father, she can file a petition for custody in the family court having jurisdiction over the matter. The court will consider various factors such as the age of the child, the preference of the child (if the child is old enough to express an opinion), the financial and educational status of both parents, and the overall welfare of the child. The father may also have the right to contest the petition and provide evidence as to why he believes he should retain custody. Sending a child to a hostel may not have a direct impact on the father's right to custody, but it may be considered by the court while deciding custody. The mother can argue that sending the child to a hostel is not in the child's best interests and that she can provide a more suitable home environment for the child. However, the father can also argue that sending the child to a hostel was necessary and in the child's best interests, for example, if he was unable to provide a stable home environment at the time. It is advisable to seek the advice of a family law attorney to understand the specific laws and procedures in your area and to represent your interests in court.