Genjutsu is the ability to use chakra to manipulate and control a target's five senses. The Rinnegan's chakra-rod binding powers is not a form of genjutsu. The chakra of the Rinnegan's Gedo, physically binds the target, unlike the Sharingan's unique brand of paralysis genjutsu, where chakra manipulates the brain to believe its being held in place.
Aoba Yamashiro also uses a chakra-binding technique vastly similar to the Rinnegan's chakra-rod binding: