Moses' father Amram was a son of which son of Levi?

Answer: Kohath

Levi's sons were Gershon, Kohath and Merari. Kohath's sons included Amram, who married Jochebed and fathered Aaron and Moses.

“These were the names of the sons of Levi according to their records: Gershon, Kohath, and Merari. Levi lived 137 years. The sons of Kohath were Amram, Izhar, Hebron, and Uzziel. Kohath lived 133 years. And Amram married his father’s sister Jochebed, and she bore him Aaron and Moses. Amram lived 137 years.”— Exodus 6:16, 6:18, 6:20 (BSB)