Mo'at is the spiritual leader of the Omaticaya in Avatar: Fire and Ash.
In Na'vi society, this role is called tsahìk. The tsahìk serves as a spiritual guide, interprets the will of Eywa, and helps preserve the clan's traditions. Mo'at is therefore distinct from the clan's political or military leadership, even though her influence extends into major decisions.
Mo'at was introduced in the first Avatar as the tsahìk of the Omaticaya and the mate of Eytukan, the clan's chief. She is also Neytiri's mother and played a central role in Jake Sully's acceptance into Omaticaya society. Her knowledge helped Jake understand Na'vi customs and the clan's relationship with Pandora.
A common mix-up is choosing Ronal, who is the tsahìk of the Metkayina reef clan, or Varang, who leads the Mangkwan, known as the Ash People. Tsireya is a Metkayina character, not the Omaticaya spiritual leader.