There are two ways you can check your Reliance Jio plan details. One is through the MyJio app and another through the Jio website - jio.com.
How to check plan details using MyJio app:
1) Open MyJio app and login using passowrd or through the SIM verification.
2) Once you open the app you can see the balance on right hand side top. If you have used only the Summer Surprise Offer or the Jio Dhana Dhan Offer and has not done any other top up for additional data or for international roaming, then your balance will be shown as zero.
3) To know the validity of your existing plan, go to my plans under the main menu button on the left hand top. it will show you the plan under which you are currently registered, its validity and the amount of SMS and data available for the day.
How to check plan details online:
1) Open the jio.com website, and click on Sign in on the right hand side top.
2) You can log in to your account using your password or a OTP, which you will get on your Jio number.
3) After you log in, you can see your Jio balance on top.
4) Just below the "Summary" heading, you can see the number of days your existing plan - Summer Surprise or Dhan Dhana Dhan - is valid for.