This article explains how to connect an Xbox 360 controller to an Xbox 360, a Windows PC (running Windows 10, 8.1, or 7), or a Mac.
How to Connect an Xbox 360 Wireless Controller to an Xbox 360
Syncing an Xbox 360 controller with an original Xbox 360 is of course the easiest process on this list. Here's how:
Turn on the Xbox 360.
Turn on the Xbox 360 controller by holding down the large Guide button in the center.