At one point there was a dispersion, or a separation of the population, referencing four different locations, ne'er again to meet, at least for millenia. Different tongues, etc. I think those that went to the Indus valley region may have eventually migrated to eastern China and Japan. I suppose you could call them caucasian, if they were originally offspring of the Nephilim.
Nin-gish-zidda was the Nephilim name for Quetzlcoatl. He was perportedly a builder, an engineer and scientist of no small fame. Egyptians knew him as Thoth. He was in charge of the mining expedition in the Americas after the Great Flood which destroyed all the mines in Mesopotamia and Africa.
(His last known location was in Mexico City. Be on the look-out for the Feathered Serpent. Reportedly still at large.:>)