DOES NETGEAR ORBI WHOLE HOME MESH WI-FI SYSTEM (RBK53S-100NAS) SUPPORT VPN PASS-THROUGH?

If "VPN Passthrough" means the router allows every device on the LAN side to reach internet destinations through VPN, then the answer is "no, the Orbi does not do this."  Individual devices behind the Orbi can run VPN through the Orbi to the outside, but each must do it separately.

Orbi does support being an OpenVPN host, so that a device "outside" can open a VPN connection to the Orbi.  Ironically, if I am sitting at a coffee shop or airport, I can VPN from there into my Orbi, and then have my internet use go to the internet from the Orbi.  It is not in a VPN at that point.  I use Orbi OpenVPN primarily to perform Remote Management on the Orbi itself.