It's possible to have any object in a nib. Literally, any object that can exist in your app can be in a nib.
However when you're doing nib-based (as opposed to storyboard-based) design, you don't usually put the view controller in the nib. The normal approach is to create the view controller in code, usually with the initWithNibName:bundle:
method. The nib will be configured with the view controller as "file's owner", which is a reference to an external object not contained in the nib. The nib contains the view that the view controller uses, connected to the VC's view
outlet.