Q: Why does the iOS 10 update not appear in settings on my iPad Mini2?

Hi

Are you sure it,s not an iPad mini 1  ios 10 starts from iPad mini 2 and upwards .

Cheers

Brian

If that's the case and you really want to update to iOS 10 at this time, you could also try the iTunes update method if you have a PC/Mac that your iPad mini 2 syncs to.

Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support

On the above page, scroll down to the section "Update your device using iTunes"