Apple iPhones have an auto login feature which needs to be disabled before connecting to JioNet public hotspot. Quick steps to disable auto-login:
Connect to JioNet Wi-Fi Network
Click on the (i) button on the right side of the JioNet SSID name
You will see the option to disable / enable 'Auto Login'
Disable the 'Auto login' feature
Now on reconnecting JioNet Wi-Fi, you should be able to access the JioNet login page.
In case the issue persists, you can call JioCare at 199 from your Jio SIM or 1800 88 99999 from any number. You can also Chat or write to us by clicking https://www.jio.com/live_chat_desktop