Afaik vSAN goes hand in hand with ESXi so clicking on an ESXi host in Hosts&CLusters should show the version in Summary tab next to Hypervisor.
If you are looking for the on-disk format then for example select Cluster object in Hosts&Clusters -> (vSAN) Disk Management -> View Disks will show diskgroups and Disk format version.
Just to add to @JaSo2 's reply, see https://kb.vmware.com/s/article/2150753
André
Afaik vSAN goes hand in hand with ESXi so clicking on an ESXi host in Hosts&CLusters should show the version in Summary tab next to Hypervisor.
If you are looking for the on-disk format then for example select Cluster object in Hosts&Clusters -> (vSAN) Disk Management -> View Disks will show diskgroups and Disk format version.
Just to add to @JaSo2 's reply, see https://kb.vmware.com/s/article/2150753
André