Open the MyJio app
Sign in with your Jio number
Tap on JioTunes
Search for a song or browse the available songs
Select the song you want as your caller tune
Tap Set as JioTune
Confirm the activation
Wait for the confirmation message from Jio
To change the caller tune, repeat the same steps and select a new song
To deactivate, go to JioTunes in MyJio and turn off the active JioTune