The confusion of languages is the result of the disobedience of the descendants of Noah’s three sons by not following God’s command to “…Be fruitful, and multiply, and replenish the earth” (Ge 9:1). Instead they “…2found a plain in the land of Shinar; and they dwelt there….4And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, lest we be scattered abroad upon the face of the whole earth” (Ge 11:4) Bad move! “…the LORD did there confound the language of all the earth: and from thence did the LORD scatter them abroad upon the face of all the earth”(Ge 11:9)
From Ge 10 (‘Table of Nations’) and research by Bodie Hodge there may be two lines of descendants involved. 1) via Japheth’s son Madai (Medes, Aryans, India incl. today’s Bhutan) also Japheth’s grandson Togarmah, (some who moved to Mongolia, China and Russia), and 2)via Shem’s great-grandson Joctan’s 13 sons (Ge 10:26-29) populated Arabia, India incl. today’sBhutan, Indonesia and beyond?