Will Apple reject my iOS app if it has unused UIViewControllers? Will apple reject my iOS app if it has unused UIViewControllers?

I have many UIViewControllers in the Storyboard. However there are few of them I am leaving for next releases as they need more testing. Their functionality is implemented though. 

Can I submit the app with these conditions?

The unused UIViewControllers are isolated from the used ones, So there are no segues between unused UIVC and a used one.
The app won't get rejected.

Apple don't browse the source of your app—they're testing the functionality from a user's point of view. Private API detection is left to iTunes Connect.

You should still try to remove unused code from your app to make the app as small as possible for users.