Help with code I want to create

Someone has an idea how I can do this shown in the photo

It's not really clear what you're asking.  Simply posting a photo of a screen and asking for code that creates it probably won't get you very far.  Have you tried anything?  Are you working with an example application?  If you have nothing but a photo and just want someone to hand you code based on that photo, you're probably going to need to hire a developer.

How can I create the same session in RSG?

HI,

Did you already read/experimented with the tutorial application that Roku has?
https://sdkdocs.roku.com/display/sdkdoc ... pplication

As joetesta already said, we can't really help you when you just ask for code to accomplish this. 
Have a look at the different grids that Roku offers and play around with them. See if you can get items with different sizes to be rendered correctly.  

Thanks, I'll let you know how it was.