Hello Sreenivasa007,
It looks like you are having an issue connecting to the App Store.
You can find steps to follow to try to resolve this here: If you can't connect to the App Store, iTunes Store, or other Apple services - Apple Support
If you are still having an issue after working those steps, please go to iCloud.com and confirm you are able to log in with the same Apple ID and password being used on the iPhone.
Be sure to test using a different Wi-Fi network.
If you are using a VPN or other security software, be sure to disable to remove and test again.
If you continue to have an issue, post the details of what is happening.
Have a great day!