Headset not connecting

Turn off and disconnect all controllers from the Xbox 360 and disconnect the wireless headsets from the controllers.

Connect the wireless headset to the Xbox 360 using the USB cable. Turn on the wireless headset.

Sync the headset to quadrant 1 by pressing the "Connect" button on the on the Xbox 360. Then press the "Connect" button on the wireless headset for two seconds. Do not continue to press the "Connect" button on the wireless headset, as this will change the
quadrant to which it is connected. If the headset now works without the controllers attached, the problem must be with one of your controllers. If the headset still does not work, then the problem is with the headset.

If the headset is only a Bluetooth headset, then it cannot be connected to the Xbox, as the console does not support Bluetooth. However, you can connect a wired headset to the controller via 3.5 mm audio jack. If the headset can be connected that way, then you will have to connect via the wire.

Hey there. I assume you're talking about the official Xbox wireless headset. Have you tried the following?

The headset can’t connect to a specific controller

Try the following:

Unplug any wired headsets from the console.

On the wireless headset, press the connect button. Lights on the wireless headset and on the controller are lit when they are connected. If the headset connects to the wrong position on the controller, press the connect button again to switch to the next
available position.

If your headset still won’t connect, try this:

Disconnect all other accessories from the console.

Turn off all wireless controllers:

Press and hold the Guide button on the controller for three seconds.

Confirm that you want to turn off only the controller.

Press the power button on the wireless headset.

Press the connect button on the console.

Press the connect button on the wireless headset. The lights around the console power button will spin and blink once. The position that remains lit is the position of the wireless headset.

If you want to test if the wireless headset will connect to the other positions, press the connect button again. The wireless headset connects to the next position.

Try to connect your wireless headset to your console again

The easiest way to connect your headset to your console is to complete step 2 (plug the USB charge cable into the console and turn the console on). If you've completed step 2, unplug the charge cable from the headset and skip to step 4.

Another way to wirelessly connect your headset to your console:

Turn on your console.

Move the mode switch to Xbox (Green) on your wireless headset.

Press the power button on the headset for two seconds. The lights will flash green.

4. After the headset plays the startup sound, press and hold the headset’s connect button for two seconds.

5. Within 20 seconds of pressing the connect button, press and release connect button on your console.

The lights flash green three times once your headset is connected to your console. Your headset will now automatically connect to your console whenever you turn on your headset in Xbox mode.

Note If your headset doesn’t connect within 20 seconds, the lights resume flashing slowly. If this happens, repeat steps 4 and 5. The headset can take up to 10 seconds to connect to your console.

The headset is assigned a position on the ring of light around the console’s power button. Each connected controller is assigned to one of four positions, and each controller can have an associated headset.

Does it not connect via any of these ways?
support.xbox.com/.../connect-compatible-headset

Which headset is it?