I don't know what the limitations will be in terms of numbers. Some mixed-race characters are supposed to be possible. The mixing allowed will probably follow geographic lines, so Brudvir-Janoa mixes won't be likely. You will get to choose a mixed-race character if you can find a family of mixed race with an available child slot.
Member of Immortalli within the realm of Tamriel. Explorer and weapon crafter. Restoration Ecologist