No, the remote control is not included with the Power Macintosh 5400/120. However, there are two other options available to you.
First, you can contact a local, Apple-authorized service provider and inquire about purchasing the remote control which is included with the Apple TV/Video System. The service part number is 922-0549. Service providers may not have service parts available.
You may also use any remote control which uses the Sony command set. This includes Sony TV remotes, and universal remotes which can be programmed with the Sony command set.