To know the validity of your current subscription, simply go to the Pro page on your JioSaavn app and you'll see all the details about the purchase. To find the Pro page - click on the "Pro" option on the home page which appears at the bottom of the screen.
If you subscribed through Google Play Store or iTunes, you can find your renewal date in the subscription settings of the respective app, or by checking the invoice from Google or Apple.
You can also head to the website and check? Ensure you are logged in with your account details.