If your app is using multiple orientations then you need to define them in the Project Target summary. e.g Portrait, Landscape left & Landscape right.
If you are having your device working for iOS5, use the following method(deprecated in iOS6) for rotating to particular orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
If you are having your device working on iOS6. you should use the following methods.
– shouldAutorotate – supportedInterfaceOrientations & – preferredInterfaceOrientationForPresentation
If your app supporting both versions then you could keep the both methods and check if your view controller is responding to the particular method by
if ([self respondsToSelector:@selector(methodToCheck)])