Mango tree is the most evolved and complex organism. It is an eukaryotic, multicellular, autotrophic terrestrial plant. It is an angiosperm (seeds are covered). Its reproductive organs are aggregated in a flower and therefore it is called a flowering plant.
Bacteria are prokaryotic unicellular organism and fungi are heterotrophic, simple thallophyte with no body differentiation. Therefore, both of these are simple organisms.