My right earphone isn't working but the left works fine

Have you tried another set of headphones? If so, and they work, then it could be a problem with the set of headphones. Make an appointment at the Genius Bar of the nearest Apple Store to have the headphones checked.

I tried all of these methods but still my right earpod doesn't work, but the earpod remote works.

Try with anotHer pair of earphones. If they do work, perhaps your earphones are broken.

iF neither earphone works go to General Settings/general and check if that the audio is not selected as MONO

Remove the headphone jack from the device. Wipe it off to ensure it is not dirty, then re-insert it into the headphone port. Make sure it seats fully into the port. Make sure there is no interference with a case. If that does not correct it, then go into Settings>General>Accessibility, scroll down to the Hearing section and see if the balance is set in the middle, and not to either side.

You can also check this one

Adjust the balance. Go to Settings > General > Accessibility, then drag the Left Right Stereo Balance slider.