Im 17 in tennessee, can I get married without parental consent? Or be emancipated?

In Tenn you can not be emancipated. You also can't be married till you are 18 without a parent or guardian signing with you. It is possible to have your brother being he is 21 to take guardianship over you but you will have to have it processed through the court. He should able to get the forms at the court clerk in your county or the juvenile court office.