RRT or Rrt may refer to: Radio Reconnaissance Platoon Railroad Tycoon (series) Rainbow Round Table Rapidly exploring random tree Reference Rendering Transform (Academy Color Encoding System) Registered Respiratory Therapist Renal replacement therapy Randomized response technique Rational root theorem in mathematics Refugee Review Tribunal in Australia. Recommended Replacement Time (In Pacemaker and Internal Defibrillator, time to replace the device because of exhaustion of the batteries) Rapid Relief Team