Imported cluster network requirements

Some use case:

  1. Rancher Server is running in the cloud and managing internal cluster (all VM’s in the cloud)
  2. Several VM’s are running in home/on-prem network (behind NAT) and form external (to Rancher) K8’s cluster.

Is it possible to manage these two clusters using the same Rancher?
What will be the network requirements (open ports, VPN, …)?