We recommend using Helm, a Kubernetes package manager, to install Rancher on a dedicated Kubernetes cluster. This is called a high-availability Kubernetes installation because increased availability is achieved by running Rancher on multiple nodes.
In a standard installation, Kubernetes is first installed on three nodes that are hosted in an infrastructure provider such as Amazon’s EC2 or Google Compute Engine.
Нет там про rke ничего
Вот что они пишут к 2.5
The cluster requirements depend on the Rancher version:
As of Rancher v2.5, Rancher can be installed on any Kubernetes cluster. This cluster can use upstream Kubernetes, or it can use one of Rancher’s Kubernetes distributions, or it can be a managed Kubernetes cluster from a provider such as Amazon EKS.
In Rancher v2.4.x, Rancher needs to be installed on a K3s Kubernetes cluster or an RKE Kubernetes cluster.