Korah is not mentioned among the sons of Eliphaz, and therefore is thought to be his grandson. There is another Korah, Genesis 36:14,18.
Related Commentaries of Genesis 36:16
Genesis 36:16
16 Duke Korah, duke Gatam, and duke Amalek: these are the dukes that came of Eliphaz in the land of Edom; these were the sons of Adah.