What were the characteristics of the imperial systems of both the Aztec and the Inca empires?

You might mean their political structures. One thing in common with the Aztecs and the Incas is that both employ a governing system somewhat similar to a federal style of government. Aztecs, whose empire included several distinct cultures, ruled indirectly by simply asking tributes. The Inca empire have four administrative regions called suyu, which was effectively ruled by an Apu, which has no connection to the royal family ruling the Inca capital Cuzco.