Is it permissible for a brother to sever ties with his sister because he refuses the suitor to come to the house, and then assault her after her marriage, claiming that the marriage is impermissible?

The fiancée is a stranger to her suitor. Therefore, it is impermissible for him to be in seclusion with her, or to go out with her without aharam, or to speak with her without necessity. As for the brother's objection to hosting the suitor, if no transgression of Sharia occurred, then his objection is baseless; rather, it is ignorance and disobedience. However, if Sharia violations occurred, such as seclusion or seeing her in inappropriate attire, then his objection is acceptable, but within the limits of Islamic law regarding enjoining good and forbidding evil with parents. His hitting his sister and accusing her is forbidden, and he must repent and seek her forgiveness.