The game puts you in the shoes of an orphan kid who has recently escaped an evolving civil war in Vault 18. I'm not really sure why it's titled Project Brazil since it has nothing to do with the country at all, but the best guess I can give is because of the sheer scale of the mod. With that said, keep in mind that these aren't only just mods, but they are full-fledged experiences of their own, that come with a whole new story than what you would experience on a normal playthrough of New Vegas.
Some of the content creators out there still have some unfinished business left on their projects for Fallout: New Vegas and after 5 years, some of these developers are finally ready to show off their game.
