Indonesia is a vast and ethnically rich country having traces of tribes too 
Yes... it is ethnically rich (I would rather use the word "diverse"). There are more than 600 languages spoken in that country (250 of that in Iriyan Jaya), and you can imagine the richness of cultural diversity there.
why? what's wrong with the term "rich"? also it's interesting how you seem to highlight irian jaya but mistyped it.