Hi,
If you are using the HPE ROK media license, refer to the below link and go to point.63
https://h20195.www2.hpe.com/v2/getpdf.aspx/4aa4-3787enw.pdf
It says that, you have to license the physical host, it means if you have 3 hosts running in a cluster, license all the 3 physical hosts, since you cannot guarantee the VM placement, it is suggested to license all the hosts.
Regards,