Is Virtualbox Apple silicon ready?

Not yet !

VirtualboxVirtualbox

VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use.

Apple silicon status: Virtualbox in its present form will not run on the ARM-based Macs.
The app doesn't work with Rosetta 2
Additional info:
If Virtualbox ever does get translated to ARM it is highly likely that it will only be able to run VMs with ARM operating systems, not x86 operating systems like Windows, Linux, or OSX10/Big Sur & descendants.

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