You and file for divorce on grounds of adultery and cruelty by wife which is valid for divorce under section 13 of Hindu Marriage Act.
Also, you can file a petition seeking custody of a child by showing the conduct of the wife to the court and by proving that she is unfit to take care of the child. any incident which proved that she was negligent taking care of the child would also help you in this case.
You would not be liable to pay any maintenance or alimony amount to her, if the charges of adultery are proved against her.