“lived.” The Hebrew is literally “sat,” and it can refer to living in a place or ruling there, sitting on a throne. Here it likely means both.
“Og king of Bashan, of the remnant of the Rephaim.” The king of Bashan, Og, was one of the Rephaim, the descendants of Rapha, who was one of Nephilim, the “fallen ones” of Genesis 6:4. The conquest of Og and his kingdom is in Deuteronomy 3.
[For more on the Nephilim, see commentary on Genesis 6:4.]