I recently tried to download that Raven 2.0 mod for Rainbow Six 3 but I think it was taken down. Does that happen often as I thought that was a pretty popular mod.
I have two copies of the game (Rainbow Six 3 Gold)...
The Steam version has the ALLR6 set-up for MP and the optimize patch... AllR6 MP set-up The ALLR6 community has it´s own servers and a Discord channel. All very friendly folks.
The Ubisoft version has the latest version of the "Elite Counter-Terrorist" mod for SP play... Elite Counter-Terrorist Mod
You need to install the "Iron Wrath" expansion first. Also found at ModDB.
Both work just fine on Windows 10.
Here´s another way to install a game set-up... Alternate mod Install
Happy Tango Hunt!