IPHONE6

Have you tried a reset?

Restore?

If you can't update or restore your iPhone, iPad, or iPod touch - Apple ...

Try holding the Wake/Sleep button on the right side of the phone at the same time as the home button. Hold those at the same time until it restarts, so hold for about 20 secs to be safe, and then if the screen is black hold the sleep/wake button until something happens.

Were you just turning your phone on, or were you upgrading to iOS 10? Also, do you have a mac? and do you have a backup of your phone? The next step would be to put your phone into recovery mode. www.imore.com/how-to-iphone-ipad-recovery-mode