It is possible to use black seed oil for deep frying, but it is not traditionally used as such. If used in the preparation of food, it is more common to add black seed oil as a spice or flavoring.
The best oils for deep frying are peanut or safflower as they are neutrally flavored. The black seed oil is derived from the seeds of an Asian plant called Nigel sativa and has been used for a long time in the practice of herbal medicine for its health benefits supporting a range of challenges from diabetes to cancer to arthritis. Peer-review research on the medicinal benefits of black seed oil are not readily available.