Hi sasankheirandish90,
Please try clearing cache & storage of FM Radio.
Please check with different earphones and check if the problem still appears.
Please check if the problem appears in safe mode: https://www.asus.com/support/FAQ/1005163/
If the problem still appears, please provide your firmware version: Settings > System > About Phone > Software information
If there is any error message, please show us a screenshot.
Thank you 🙂