Q: Need help how to activate iphone after updating

Did you already try to update, using iTunes on your computer?

Check this article:

If you can't activate your iPhone, iPad, or iPod touch after installing iOS 9.3 - Apple Support

Just like him, i have the same problem, i tried every solutions in the article, except contact Apple 'cause i live in VietNam, and i don't know how to call them. Is there any way for me to email them instead? I tried to dial the phone number but i can not connect.

Apple has pulled the iOS 9.3 update for some devices (iPad Airs and previous, iPhone 5s and previous) due to problems with activation. You may not be able to update until a fix is issued.

See these articles for details.

http://www.imore.com/apple-working-ios-93-fix-older-iphone-ipad

http://osxdaily.com/2016/03/25/troubleshooting-ios-9-3-update-problems/