The student pilot reported that, during the landing roll, he applied brakes and the airplane veered right. He was unable to correct back to the centerline or brake effectively; the airplane exited the runway and struck an embankment before coming to rest. The airplane sustained substantial damage to the left horizontal stabilizer. Postaccident examination of the airplane revealed damage to the right brake torque plate. The right brake became stuck when actuated and sometimes required prying to release. After the torque plate was replaced, the brake functioned without any anomalies.