How To Activate iPhone through iTunes

This is how to activate iPhone through iTunes, follow these steps..

Check System status page, if iOS Device Activation is not green, wait for a while
Make sure you have the latest iTunes on your Mac or Windows
Connect your Mac or Windows to the internet
Check here for the latest version of iTunes https://www.apple.com/itunes/download/
Or if you alreade have it on your Mac or Windows, then open iTunes.
On the menu bar of your Mac click iTunes then click Check for Updates, if you are using Windows on the menu bar click Help then click Check for Updates
Connect the iPhone to your Mac or Windows with the cable connector (the one that came with your iPhone)
iTunes will recognize your iPhone in a few moment and it will prompt "Set up as New" or "Restore from Backup" then it means your iPhone has activated, unless it says SIM card isn't compatible "The SIM card inserted in this iPhone does not appear to be supported". Follow steps below.

Make sure you were not using a foreign SIM to unlocked your iPhone.
Update your iPhone to the latest iOS version
Remove your SIM car, then put it back again, make sure it is not loose
Check for updates (Settings » General » About)
Contact your Carrier to unlock you SIM card.
Check for physical damage, try using another SIM card, if it works go to your carrier and ask for a new SIM card with your number.