Is it okay to put a family member to a mental institution for the rest

he has mental illness and he is living with us and our family are toxic now because of him we are all stress by him..we want him out of our life..

Yes, sometimes it's the done thing to do particularly if you and yours are suffering and genuinely trying to cope with it. You can't help someone when you're beaten down trying to do just that. Some people are better off in institutions, while others go backwards. It's your call, and don't forget the legalities of it all as well.

The criteria for someone being admitted into a mental health facility is that they would do harm to other people or harm to themselves. If that person living with you is threatening family members or himself then you need to get a judge to make that decision for the family OR The person admits himself at the nearest mental health facility. Does this person have a mental health worker? Have you brought in outside help, including even the police department, for when this person’s behavior gets out of control?