In 31 BBY, Nim'Ri' was the head of security for House Hirskaala, a security concern in Cularin.
When one of Hirskaala's employees, Darin, was kidnapped by pirates wearing House Hirskaala uniforms, he helped out a group of people that were looking for him.
One month later, Nim'Ri was concerned about the Metatheran Cartel's actions in the Cularin system. He disappeared himself from his daily life and helped form the Cularin resistance. He might have helped decoding the password for the secret base.
Nim'Ri become one of the leaders of the group, firmly believing that their work would be the last hope of the system. He was a moderate influence between Gerta Haman's peaceful idealism and Broof Yurdel's Gungan warrior fierceness. Along with them, Nim'Ri greeted some unexpected visitors, who might have been the people who were looking for Darin one month before. They were looking into the massive disappearances as a favor to Jedi Master Lanius Qel-Bertuk. Nim'Ri and the others tried to convince them not to reveal anything about the Cularin resistance
Nim'Ri was in the base when, one month later, the Cartel found it and launched an attack with a Caarite hit force. Nim'Ri helped Yurdel against the Caarites, but Gerta Haman was seriously injured during the shootout. Yurdel was distraught at that and wanted to destroy the Cartel base with great violence. Nim'Ri believed that Yurdel was too careless and that he could get killed in the attack. The Trandoshan, an expert in Caarite tactics, organized part of the attack, including briefing some allies who were to slice in the Cartel's computers, and later he took part in the battle, co-leading the troops along with Yurdel in their attack to the Metatheran Cartel jungle base.
The battle was a great victory for the resistance, and led to the Cartel retreating from Cularin. Governor Barnab Chistor of Gadrin condecorated Nim'Ri and the other resistance leaders and heroes. Then, Nim'Ri returned to his previous post on House Hirskaala.
When the Thaereian military seemed to be exceeding its mandate in protecting the Cularin system in 21 BBY, Nim'Ri resigned his job and disappared. Although his friend Yurdel joined the nascent Cularin Militia, to build up a native defense force for the Cularin system, Nim'Ri was not seen with this group or elsewhere in the system. A rumor said that Nim'Ri had returned to his native Trandoshan planet but, as Nim'Ri had not been born on Trandosha (and as he was a known freedom fighter who would not give up during hard times and would instead threaten the threateners), this canard was an obvious hoax. Some people believed that the Thaereians had secretly killed Nim'Ri and then developed the false hearsay.