A. First off all:
Probably you are new to Cocoa and Objective-C.
a. Why don't you use buttons?
b. onOff is obviously a property. Why don't you use declared properties?
B. To your Q:
You can retrieve the views with a specific state by asking the superview for its subviews and then filter them with a predicate:
NSPredicate *clickedPredicate = [NSPredicate predicateWithFormat:@"onOff == %d", YES];
NSArray* clickViews = [view1 subviews]; // Returns all subviews
clickViews = [clickViews filteredArrayUsingPredicate:clickedPredicate]; // On-views
But you should think about storing the state outside the views. What is your app for?