Most of the world’s tribes have been contacted by now by one way or the other. Many of them have embraced modern technology and are communicating with the rest of the world. However, there is a ferocious tribe that attacks everyone who dares to enter their island, which is North Sentinel Island.
Anything else about this tribe is a mystery. They attack everyone and everything and shoot arrows at airplanes that fly above them. There was a plane that had to crash land on the island but there were no survivors.