Hey Nilay182,
Thank you for using the Apple Support Communities. I can see from your post that you’re having issues with your iPhone freezing or not responding. Having a reliable phone is important and I'd like to help get yours working normally again. I've provided a link that provides steps on how to troubleshoot a few things with your phone when it doesn't respond.
If the screen on your iPhone, iPad, or iPod touch doesn‘t respond to touch
If you still have issues with your display after following these steps, let us know and we can continue troubleshooting from there.
Regards.