Dial 199 from your Jio SIM and check the IVR details
Dial 1299 from your Jio SIM and listen for your number
Open the MyJio app and view your registered mobile number
Check your SIM card packaging or welcome letter
Send an SMS or make a call from your Jio number to another phone and see the caller ID
Check your phone settings under SIM or About Phone
Use the Jio website or MyJio account if your number is linked there