Ive been working with Fusion 13 (Apple Silicon) with a Windows 11 ARM VM configured with a custom NAT network that's IPV6 enabled.
I've successfully pinged outbound from the VM residing in the NAT network to the IPV6 address of my active network adapter.
Trying to get from the Mac to the VM proved a bit trickier (I freely admit I'm a noob on IPV6).
I was able to finally get the ping to work from the Mac to the VM using the following variants of ping6. This assumes that the Mac host is configured to have an address on the NAT network, and no port forwarding is done via NAT.
ping6 -I bridge102 fe80::537e:ef38:47d6:1c93
ping6 fe80::537e:ef38:47d6:1c93%bridge102
where bridge102 is the bridge corresponding to my custom NAT network, and fe80::537e:ef38:47d6:1c93 is the link-local address of the VM on the NAT network (obtained through ifconfig in the Windows guest). Both of these seem to force the ping to go over the bridge connected directly on the NAT subnet.
I could not get this to work otherwise. I would get "no route to host" or I would find ping just sitting there and reporting packet failures. It's probably due to the IPV6 routing tables in the host (as I admit as well I don't have a lot of experience with).