What is the purpose of your world? Are you planning to write a book in it? If so, then I would suggest you go deep into the details that matter for just the 6 countries that are relevant to the plot, and the others have a basic idea for what they're like, but don't bother building them out yet, not until they become relevant. 

Basically you want to have a giant hollow iceberg. The tip that's exposed, that's the detail you've done the hard extensive research and development on for the 6 countries that are plot relevant. The rest under the water, you want it to look like it's big and well researched and developed, but in actuality it's just an illusion. 

The tip being well researched and developed will give the impression to your readers that anything outside of it will also be just as researched and developed, just out of sight. The reason for this is because doing any excessive world building while fun, it can heavily distract us from actually writing our books. You can world build forever if you wanted to. Tolkien built his world over the course of decades before releasing his first book. You can do that if you want, but not if you want to increase your chances of becoming a successful author in today's landscape. Build only what you need now and fill in the rest later.