my iphone 6s display is not working using ios9.2.1(13D15) please help me

• Try to adjust the brightness. If the screen doesn’t respond when you adjust the brightness, open several apps to make sure it’s not an issue with only one app.
• If you have a screen protector, try removing it. Try removing your case if it includes a screen protector.
• If you see the issue in multiple apps, restart your device.
• If restarting doesn’t fix the issue, restore your device.
• If you still see the issue after you restore, contact Apple Support.

Get help with the screen on your iPhone, iPad, or iPod touch - Apple Support

As stated above, restore your device. If you still see the issue after you restore, contact Apple Support.