To install 10.6, you have to boot to the DVD. This gives you minimal MacOS X functions. I do not expect VNC is included.
So I think you may have to drag over a keyboard, mouse, and display for the basic install.
If you have a comparable Mac, you could drag a disk drive over the other direction and install on another Mac, as long as you are using a "Full Retail" DVD, not model-specific DVD.
Or you could use FireWire Target disk mode.