the Rancher management server can be installed on either an RKE cluster or a K3s Kubernetes cluster 3. Install Kubernetes (Skip for Docker Installs)In this guide, we are assuming you have created your nodes in your air gapped environment and have a secure Docker private registry on your bastion server. Obtain the images tar file for your architecture from the releases page for the version of K3s you will be running.https://rancher.com/docs/rancher/v2.x/en/installation/other-installation-methods/air-gap/launch-kubernetes/