Is it possible to install Mac OS 9 on a VM?
SheepShaver will be your best bet. There's several tutorials laying around on getting OS 9 running in SheepShaver.
All OS 9 capable machines run on the PowerPC platform, meaning that your VM software has to emulate that instead of the x86 platform.
These are pretty rare. I know only of qemu which can emulate multiple platforms, and it is mostly suited for technicians. I would go for a dedicated OS 9 emulator as suggested by https://apple.stackexchange.com/a/64963/3157