Answer

According to Jain tradition, Marichi Kumar is associated with the Parivrajak school/sect. He is described as the founder of the Parivrajak school, not the founder of a major world religion. ( encyclopediaofjainism.com)

Explanation

Jain texts describe Marichi as a prince who later became a mendicant and then established the Parivrajak path. This school is presented as a separate mendicant tradition that developed from his teachings. ( jainworld.jainworld.com)

Takeaway

So the short answer is: Marichi Kumar started the Parivrajak sect/school. ( encyclopediaofjainism.com)