Regens appear everywhere, but good regens could appear anywhere aswell. If a club has top youth facilities, they have more chance of producing a wonderkid regen. Search the u21s, u20, u18 national teams, and you will find them. or, search for 15-18 year olds by position, and the higher valued ones are usually the top regens. Scout nations one by one, using the best scouts you can get hold of.