The end-user has to download their respective operator app and follow below steps:

Airtel APP:
In Airtel app, Click on More ==> My Airtel ==> Manage Account ==> (Select the number you want to check) ==> (On next Screen) Click on Manage Services ==> Click on Activate/Deactivate DND

Vodafone APP:
In Vodafone app, Click on My Account ==>> More Services ==>> Do Not Disturb (DND)

Jio APP:
In jio app, Click on Menu ==>> Settings ==>> Click on Do not disturb