Extra space at the bottom of the view controller?

I am using a storyboard with a custom tab bar controller.

When view controllers are added through the storyboard references, with a container(embedded) view, it creates an extra space at the bottom of the view controller, ie just above the tab bar.

The dimension of the space seems to be the same as that of the tab bar height. Is there any solution for this issue?

How do I change my initial view controller?

You will be able to see how your Initial View Controller currently looks like on the left side of your screen. Simply drag the View Controller to the screen to create a new one; this option is located on the bottom-right side of the screen.

Can a view controller dismiss itself?

The presenting view controller is responsible for dismissing the view controller it presented. If you call this method on the presented view controller itself, UIKit asks the presenting view controller to handle the dismissal.

Check the following in storyboard :
Extend Edges
1. Under Opaque Bars
2. Under Bottom Bars

enter image description here