A judge awarded the Backstreet Boys star's stay-away request on Wednesday morning, November 20, at a hearing in Las Vegas, which Aaron didn't attend.
The "I Want Candy" star has been forbidden from having any contact with his brother or his family until November 2020.
Aaron has also been ordered to stay from his twin sister, Angel, after she accused him of threatening behaviour.
During the hearing on Tuesday, the judge also told Aaron he's too dangerous to possess guns, prompting the singer to lose his cool in court.
Nick first sought legal protection in September, after Aaron allegedly threatened to kill his pregnant wife.