Q: I can not send text messages in i phone 6 , IOS 9.0.2. Please help.

Hi! Check your Wi-Fi/Cellular connection and if everything is fine there, follow the steps below.

Take a look at this Apple Support articles:

iOS and OS X: Link your phone number and Apple ID for use with FaceTime and iMessage - Apple Support

Get help signing in to Messages, FaceTime, and Game Center - Apple Support

Reset your network settings.

Settings - General - Reset - Reset Network Settings

Reset your device. This won't delete your data stored on the phone.

• Press and hold the Sleep/Wake button
• Press and hold on the Home button
• Keep holding both buttons until the display turns off and back on with Apple logo on it.

Alternatively, you may go to Settings - General - Reset - Reset All Settings

https://support.apple.com/en-us/HT201559