1) Enter the below website to install game fix mod.

https://www.gamepressure.com/download.asp?ID=51022

2) After download extract the entire contents into the game folder to the installed path
Example : (D:\Steam\steamapps\common\Rainbow Six 3 Gold)

3) To play Athena Sword(Expansion) install it from steam and follow the below instruction after
installing and do not delete the base game to play both expansions.

Instruction -> Open the game Navigate to the options->custom game and select the Athena
Sword expansion to play it.

4) Installation of Iron Wrath(Expansion)

Copy and paste this link in browser (https://www.moddb.com/games/tom-clancys-rainbow-six-3-raven-shield/downloads/rainbow-six-3-iron-wrath-manual-installation) and download the file.
Open Readme.txt and follow instructions to install it.
Ensure that your Raven Shield base installed to play the expansion.
To play, start the game, go to Options, choose Custom Game, and activate Iron Wrath.