There are a few key details you'll want to focus on when picking out a mouse for Rainbow Six Siege. As a competitive first person shooter, you obviously need something precise and ergonomic. A high-quality sensor, as well as support for high DPI settings makes for a great gaming mouse. These two factors will help you improve accuracy and overall consistency throughout your R6S gameplay.
We mention ergonomics because comfort is key when you're primarily using your mouse during gameplay. Extra programmable buttons are also useful if you wish to bind weapons or gadgets directly on to your mouse to avoid hindering your movement on keyboard.