I am presently writing (not much, but still writing) a fanfic that shows what happend to Brazil in the Fallout Universe. Some other authors also write in this setting. After a war with Argentina, both countries nuked each other to hell and post-apoc holocaust began. In Brazil, during the old military governament's times, there was a lot of propaganda about how Brazil would be "The Country of The Future." My idea is that the pre-war Brazil actually WAS this ideal country of the future, which then turned into a dystopia and then, BOOM, nukes start to fall.
Since it's far away from the Fallout settings, I had to create new organizations. New organizations include (these are translated names):
The Three Lakes Confederation, a starship-troopers style democracy mixed with FOT's Facist Brotherhood of Steel that was created by a army battalion that survived the war in their military base and is one of the most technologic advanced factions, BOS level, even. They live in Mato Grosso do Sul, in the Brazilian Middle-West.
The United Kingdown of Caxias and Itaipu, which is a monarchy that rules over much of the south region of Brazil and is recently undergoing a civil war. They also have a rivalry with the Confederation.
There are also two massive Organized Crime Mafias that fight each other in the southeast region:
Red Command, which is a faction of criminals that rules over Rio de Janeiro and commands all slavery, drug dealing and prostitution in that state. They are so influent that even the nation-states of the area fall to their influence.
And there's also the Fifth Command of the Capital, which is a group of gangsters from São Paulo. Both RC and FCC fight each other to control organized crime in the brazilian south east, with massive civilian casualities each time they clash.
There's also many small cities, like La Putteiro, which is a small village near Brasilia populated mainly by a spanish-latino population. The name means exaclty what it says on the tin. It's a hub of prostitution in the region, but also has some farming. The Confederation tries to influence La Putteiro to join them, but it never had any sucess.
Other cities include Obadias, which is a small trade outpost between La Putteiro and another city called A Taverna.
The Tavern is a heavily-fortified tavern-trade outpost between the Brazilian middle west and the south east. There are many nearby villages that trade with The Tavern. What nobody knows is that bellow The Tarvern exists a vault-like underground shelter where the founders of The Tavern came from. That vault-like underground shelter built by a rival company of Vault Tec that came to Brazil still exists to this day and is still populated by many people. The Tavern is nothing but a front they use to trade for what they need without being instantly a big target of any scavengers nearby.