Unable to use touch id on my iphone 6s

I was using touch-id on my phone. For last few days home button's response started deteriorating. I disabled the touch-id to avoid using it and started using Assistive-Touch. In subsequent 2-3 days, I realized that home button has started responding as earlier. Now I am unable to enable touch id again.

Below is the Screenshot of current settings on Touch ID and Passcode:

As you can see all options are either greyed out or turned disabled. I can't change any of it nor able to add fingerprints (Greyed out). Not sure if it's relevant but i was able to change my passcode though.

There's a possibility that my Touchsensor hardware is faulty but home screen button is certainly working.

Thanks for your time, please respond if any of you have passed a similar issue.