My right side headphones is not working?

Tanvi Snayal first check your accessibility settings (settings - general - accessibility) to make sure the volume is balanced between both sides. Anything after that is most likely a bad ensure the volume is equally balanced between both left and right sides. If all that checks out okay, you want to do a reset

1. Turn your headphones off.

2. Enter pairing mode by pressing and holding the volume+ button for 5-7 seconds. Your headphones will turn on, and then the LED light will flash red and blue.

3. Press and hold the multifunction button, volume+ button and volume- button simultaneously for 3-5 seconds. You'll hear beeps and/or feel vibrations.

4. Turn your headphones off.

Your headphones are now reset and can be re-paired to your device.

Anything after this would require a teardown and possibly replace the "speaker". Definitely not a fun thing to do but it might be possible Aftershokz Trekz Titanium Teardown