No, you cannot send an adult to Alcohol Rehab if that adult is competent. Even in the case of an adult you could send, rehab would be of very little help if the adult did not choose to do it themselves. Rehab for an alcoholic is really a lifelong commitment and hard work, and it isn't simply a matter of withdrawing someone. Such is the case with drug addictions as well. People will often enter prison, be withdrawn medically from drugs, yet return to use immediately upon release, and the same is true of alcohol. More than a few in our homeless population came to be there because of chronic substance abuse. Sorry for all you are all going through.
Who lives in your brother's house is your brother's decision.
Who lives in your house is your decision.
Where your father goes or lives is your father's decision, subject to the usual limits that apply to us all - for example, he can't just decide he's going to live in somebody else's house with that somebody's agreement.
Unless your father is mentally incapacitated AND you have formal legal authority to act on his behalf (power of attorney or guardianship, for example), then you cannot make decisions for him and of course will need his consent before you can arrange his admission to rehab.
Who lives in your house is your decision.
Where your father goes or lives is your father's decision, subject to the usual limits that apply to us all - for example, he can't just decide he's going to live in somebody else's house with that somebody's agreement.
Unless your father is mentally incapacitated AND you have formal legal authority to act on his behalf (power of attorney or guardianship, for example), then you cannot make decisions for him and of course will need his consent before you can arrange his admission to rehab.
What does your father want to do?