I have a Subaru Tribeca 2011 and i want to change the spark plugs. Does the american spark plugs fit the cars made in USA sold in Brazil?

Yes, American made spark plugs will fit any car made world wide and sold world wide. You just have to select the correct spark plug for that vehicle. I would suggest you replace your sparkplugs with the same exact ones that are in there from the factory. The owners manual will show that info, and sometimes it is shown on a label in the engine compartment.

My information shows that your 2011 Subaru Tribeca originally came with NGK 7505 Laser Iridium sparkplugs #SILFR6C11. They are about $10 each but they are probably the highest quality plug made for your vehicle. You can confirm my info by comparing with the plugs you take out. Gap them to 0.044 inches. You use metric in Brazil so you will have to convert 0.044 inches to metric, IF the gap needs adjusted.