Is it possible to put all games on all regions xbox has?

the availability of a game in a bazaar will depend on the distribution company and the legislation of that country. there are times when some games are censored and don't reach certain countries. other times for business reasons....

It has to with two things. The first is the developers. They have to figure out how to support the languages, how to edit their game to "make sense" in different cultural regions, and they have to figure out how to make them appealing through advertsing
and exposure in that market. The second reason is because of regional governments and the way they grade and restrict content for media. Often times that's one of the biggest reasons ganes don't make it to certain markets.

Most games are 100 percent avaliable in America because we have arguably the most relaxed laws about games and media. Therefore our market would be more appealing for developers than say China or in your case Brazil.

Like Smwutches said, some publishers don't put their games in certain regions because of any rules and regulations that may interfere.

That would be something that's up to the publishers/developers. In some cases it's down to rules and regulations in those regions for those games.

That would be awesome if they could do that. But sadly, depending on the publishers/developers, and the actual rules from the countries themselves. Some regions ban certain content, therefore, region based games.