Is it permissible for a Muslim to sever ties with his disobedient brother who transgresses against his family?

Kinship ties are obligatory, and severing them is forbidden and considered one of the major sins, based on the Prophet's (peace and blessings be upon him) saying: "A severer of kin ties will not enter Paradise." The commission of sins by a relative does not negate their right to kinship ties. Rather, it is obligatory to enjoin good upon them and forbid evil from them, and this is one of the best forms of maintaining kinship ties. However, if it is highly probable that boycotting them will lead to their reform, then it is permissible to boycott them at that time.