Xbox 360 Controller "Sign In": Not a Thing

You cannot "sign in" to an Xbox 360 controller. It's a hardware input device, not a platform with accounts.

Connecting to Devices:

• Xbox 360 Console: No controller sign-in; sign in to Xbox Live on console for online features.
• PC: Pair via Bluetooth/USB; install drivers if needed. No controller login.
• Mobile (Android/iOS): Use compatible app (e.g., Xbox Game Streaming); sign in to service, not controller.

To access online features, sign in to your account on the host device, not the controller.