You do not need to know the proxy version that’s running on your vCenter/ESXi server(s). onQ is intelligent: If it detects there is a different proxy version on the vCenter/ESXi server(s) than what onQ currently has, onQ upgrades the PN proxy to that version.

As outlined in (Agent‑less Windows/Linux PNs) Update PN Proxy software, onQ automatically updates the PN proxies and, in the event that the vCenter/ESXi server(s) is unavailable, continues to retry. However, you can use the alternative method outlined in To re‑enroll a proxy PN: if your PN proxies are in a state that require a manual upgrade.