Hello farhan_hasin_arik,
Welcome to Apple Support Communities!
We see you viewed the Apple Support page for If your left or right AirPod isn't working - Apple Support
Were you able to complete all the steps listed on the Apple Support page detailing the issue?
"If there's no sound in one AirPod
- Make sure that your charging case is fully charged.
- Place both AirPods in your charging case and let them charge for 30 seconds.
- Open the charging case near your iPhone or iPad.
- Check the charge status on your iPhone or iPad to make sure that each AirPod is charging.
- Put both AirPods in your ears.
- Play audio to test both AirPods.
- If an AirPod still isn't working, reset your AirPods or contact Apple Support."
Use the link in step 7 to contact Apple Support page if the issue continues after resetting the AirPods.
We hope this helps to get the right AirPod working normally again.
Cheers!