Hi ajeet16,
Welcome to the Apple Community.
Seems you need a strong wi-fi or internet connection for FaceTime, and wi-fi (or cellular SMS plan) for Messages.
Wondering if you get an error message that would help point to a solution.
You may need sign in to your Apple ID on your device to use FaceTime and Messages:
Sign in with your Apple ID - Apple Support
Else, if you have set up your device for FaceTime and Messages, and have really tried everything there is to try:
What to do:
If you can’t turn on or sign in to iMessage or FaceTime - Apple Support
If you can't make a FaceTime call on your iPhone, iPad, or iPod touch.
If you can't send or receive messages on your iPhone, iPad, or iPod touch
If needed:
The FaceTime Support Team's Website:
FaceTime - Official Apple Support