Thanks guys for the solution.

The easiest way is to install OperaVPN app in your phone.

1. Install OperaVPN app in your phone (using 4G/LTE connection first)
2. Connect back to your WIFI.
3. Launch OperaVPN, follow the on screen instructions.
4. Recommended to choose United States as the region.
5. Go back to AppStore and try updating it.
6. Turn off OperaVPN once you have done updating.

Hope the above helps.