Question

name atleast three nomadic tribes in the tundra region

Answer 1

Some of these peoples are nomadic reindeer herders, living in the tundra (arctic plain); others, who live in the forest tundra or taiga (coniferous forest), rely on a mixture of reindeer herding and hunting and gathering, and often live in settlements.

Answer 2

In physical geography, tundra  is a type of biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russia
from the Kildin Sami word  meaning "uplands", "treeless mountain tract".Tundra vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline.