Rinchen was a monk at Det-Sen Monastery. He was one of the higher lamas.
When Khrisong wanted to let the robot Yeti kill the Second Doctor, he objected, thinking Khrisong should consult with the Abbot. He set up a spirit trap around the captured Yeti in the monastery.
He was suspicious of Victoria Waterfield, calling her a "devil woman," because she tried to explore the monastery against orders. He had Khrisong imprison the Doctor and Jamie McCrimmon. Rinchen was searching for Victoria when the robot Yeti attacked the monastery in order to frighten the monks away from the monastery. He tried to stop the Yeti from destroying the monastery but was crushed to death when one of the Yeti pushed the Buddha statue on top of him. (TV: The Abominable Snowmen)