Looks like nothing older than Leopard Server (10.5). But I suppose you could try.
For the record, here is the complete list:
Guest Operating Systems
- Windows 10
- Windows 8.1
- Windows 8
- Windows Server 2019
- Windows Server 2016
- Windows Server 2012 R2
- Windows 7 (SP0-SP1)
- Windows Server 2008 R2 (SP0-SP2)
- Windows Vista Home, Business, Ultimate, Enterprise (SP0-SP2)
- Windows Server 2003 R2