I even dont understand the meaning of Which theme highest paying. Are you talking about ad formats or a web site theme?
I think the original poster is talking more about the layout on the screen and which one is actually optimized for maximum clicks. There is no quick answer here - I will say that generally speaking ads on the top left of the screen get great clicks as this is an area of the screen many people look at when first going to a page. But it's all dependant on the site and the content as well - Focus on great content is probably the best thing you can do to bring web traffic to your website - Then you can start testing different ad layouts and find the one that works best for you. Good luck!
I think, you should try the search button. Anyway, there is a correlation between the country and the theme.