Nanotechnology is a multidisciplinary field that will make our life simpler and safer and mitigate our impact on the surrounding environment. With the recent advancements and transformations in the available networking and communications paradigms, embedding Wireless Nano Sensor Networks (WNSN) with various objects, sensors, and devices would add a new network paradigm. This paradigm is known as the Internet of Nano Things (IoNT). Seamless interconnectivity among nanonetworks with the available communication networks and the Internet requires developing new network architectures and new communication paradigms while addressing the various technical challenges. Routing protocol is one of the most essential requirements in WNSN and IoNT due to the different nanoscale constraints. This routing protocol must accommodate nanoscale communication's characteristics while guaranteeing the data and information transmission. This study aims to give insight into WNSN and IoNT paradigms and present a comprehensive review of a large number of existing routing protocols adapted to nano communication's characteristics and features.