Well, that's according to AMD/ATI. They said it requires 10.3.6. It's on page 1. If it runs in 10.1, it's unsupported but it will still run or the system is able to recognize it as a graphics card and run it. There is no OS 9 driver for that. Also see http://www.mac-forums.com/forums/ru...1312-os-9-drivers-radeon-9600-pro-pc-mac.html
The driver doesn't exactly exist for OS 9. The drivers on the driver link may be able to recognize it as a graphics card and run it.
This doesn't directly answer your question but it might help: The best Apple-shipped card for OS 9 was the GeForce Ti 4600. The best Radeon was the 9000 Pro. Both of these were options on the last OS 9-compatible machine in 2003 (I really regret selling that computer!)
Yes; I was able to use a 9800 in 9.2.2 without acceleration.
Side note: I installed the ATI Universal drivers on a Rage 128 machine and it completely broke rendering in Quake. It's probably best to not install unless you need it