Accessing parent view controller

I have a mainViewController with a container view in it. I'm trying to access theMainViewController from the container view.

Here is my code:

self.theMainViewController = (theMainViewController *)self.parentViewController;

NSIndexPath *indexPath = [NSIndexPath indexPathForRow:idx inSection:0];
[self.theMainViewController .tableView selectRowAtIndexPath:indexPath animated:YES scrollPosition:UITableViewScrollPositionBottom];

This doesn't work. self.theMainViewController gives a nil value when I make an nslog of it. I then replaced:

self.parentViewController

to:

self presentingViewController

and it gave me the same results. How can I access the mainViewController from the container view's class?

Update

This is my setup: Static table view inside UIViewController [Xcode 5] (I can't add images, so the image posted in that answer, is the same as my setup.)

You can use "prepareForSegue" in the parent view controller to pass self to the container view like so:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
     if ([[segue identifier] isEqualToString:@"containerview_myIdentifier"]) {

         ContainerViewController *vc = [segue destinationViewController];
         [vc setReferenceToParentVC:self];
    }
}

Where you create a synthesized property in ContainerViewController of type ParentViewController and set that property to self.

Here is what you should see in storyboard: