In Jain Dharma, a Tirthankar is indeed a “yati” in the sense of a renunciant or yogi who has left worldly life and attained the highest spiritual state. However, there are important distinctions:

• A Tirthankar is a perfectly enlightened soul (Arihant) who has conquered all passions and attained kevala jnana. They are revered as supreme teachers who establish the path for others.
• After achieving liberation, a Tirthankar remains in a state of omniscience and does not roam as an ordinary monk; they are not ordinary ascetics, but fully liberated beings (siddhas) who continue to guide through their teachings.
• The term yati more commonly refers to renunciants who have taken formal vows and live as monks today. Tirthankaras themselves are greater beings who have preceded as renunciants in past cycles and then perfected themselves to become Arihants and, ultimately, liberated.

There can be slight differences in wording between Digambara and Śvetāmbara traditions about titles and descriptions, but the core idea remains: a Tirthankar is a supreme renunciant who has shown the path to liberation for all beings.

If you’d like, I can give a simple example or quotes from canonical texts to illustrate how a Tirthankar is described as a renunciant and teacher.