Are there any guidelines by Apple on what content apple TV app should have We are in the process of developing app for Apple TV, are there any guidelines that app should be either a video playing or gaming app, can I submit app with just readonly content like an iOS app and still it will be get approved by apple?
From this link I found the following about the Human Interface Guidelines. There is more info at the link.
Apple TV apps should feel natural and intuitive. Users should instinctively know what to do and where they are at all times. Use the provided layout grids, keep the text legible at a distance, and avoid cluttering your interface with unnecessary visual adornments.
Apple TV uses a focus model for navigation. People use the remote to move through interface elements such as movie posters, apps, or buttons, highlighting each item as they come to it. An element is considered focused or in focus when the user highlights the item but has not clicked it. Make it clear at a distance when something is in focus. Implement expected button behavior so it’s impossible to get lost during navigation—clicking an item with the remote takes you deeper into an app’s hierarchy, pressing Menu always takes you back.
There is much more info at the link above.