my iphone 6s is stolen i had activated find my iphone but now the device is not showing on my icloud on find my iphone please suggest what to do.

I currently have same issue. Apple Support and Apple Store were ZERO help. So much for paying thousands of dollars for a family pack of iPhones that the feature doesn't work when needed most. Did you ever get resolution?

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

If you enabled Find My iPhone and the iPhone is no longer showing up in iCloud, then the device is off or offline. What do you expect Apple to do? They can't change the laws of physics.

I would expect that Apple prevents someone else from using my iPhone by keeping it locked.