Selris was the leader of the Gonds when the Second Doctor, Jamie and Zoe landed on their homeworld.
His official duties mostly seemed to revolve around announcing which of his people had been selected as “high minds” by the Krotons, and then conducting them to their new responsibilities.
He was relatively reluctant to challenge the status quo, as evidenced by his disapproval of his son Thara’s attempts to dissuade”high mind” Vana from taking up her new duties. However, even though he verbally rejected The Doctor’s assertedition that the Krotons were killing his people, he did not stop the exploration of the possibility.
Once enough evidence had been collected to support The Doctor’s theories, he actively assisted in the rebellion against his overlords. In the end, he died trying to help The Doctor and Zoe destroy the Krotons’ dynatrope. His death was a noble one as his actions almost immediately led to freedom for his people. His son followed in his footsteps and became the Gond leader after his death. (The Krotons)