What race are the people Native to Siberia?
Human. There are no biological races in humans. Race is entirely a sociological construct not a biological one. There is more genetic variation within supposed races than there is between them.
Proto-Mongoloid for the most part. The Paleo-Siberians are related to modern day Native Americans and exist in regions like Kamchatka while you have Turkic groups like the Yakuts, Tuvans, Bashkirs, etc. in areas like Tannu Tuva, Yakutia (Sakha), Bashkiristan, Tatarstan, etc. A third of Proto-Mongoloid ancestry originated with the Eastern Hunter Gatherers and you have some Indo-European remnants coming from the Corded Ware culture, so many of the Asiatic Siberians have European admixture within their genome, as do Native Americans.