You must care a great deal for mother to reach out to us for help.
Not sure how the laws work in your country regarding an unwelcome person in your home. You can always reach out to your local police and ask them if there are any laws that protect your brother. Here in the US if a person has established residency you have to go to court to have them evicted from the home.
I'm not sure what "signed on" means. Is he breaking any laws by not signing on?
Has your brother ever threatened your mother? If she is afraid of him these are things you can discuss with your local authorities.
