Setting up TC with Airport utility

Are you saying that the Time Capsule is already set up and configured...providing a wireless network with a name and password of your choice.....and you cannot connect the iPad to the wireless network that you have named?

Or

Are you saying that you are trying to use the iPad to set up and configure the Time Capsule intitially, so that it will provide a wireless network, etc?

Please try the following:

On the iPad home screen, tap Settings

Tap WiFi

Under the heading of Set Up a New AirPort Base Station....

Tap Time Capsule

AirPort Setup will open up and walk you through the setup.

Once the Time Capsule has been configured.....then....you can use AirPort Utility to change or modify settings.

Glad that helped.

Not sure why you marked your "thanks" as the solution to your question, though.

Hopefully, other users with the same question will figure things out.