no ring sound and I have checked the sound volume at the phone side
Welcome to iMore! Which phone is this? Is it new? Has it worked before? If new, have you checked for cellophane plastic or any other debris covering the speakers? Did you go to Settings > Sounds > Ringtone > set a tone and vibration? Did you pull up the control center from the bottom and turn volume up there? Did you try a hard reset?
Hold the top or side power/sleep button and the home button at the same time until the Apple logo appears, then release.