Please feel free to disagree with my answers, as these are probably wrong, but this is what I remember:
Kanto: The area around Tokyo, Japan
The Orange Islands: The Phillipenes and Indonesia
Johto: Just south of Kanto's Inspiration, around where the original capital was in ancient times
Hoenn: The Florida Keys
Unova- New York City
Kalos -France (I mean, what other capital has a massive historic tower in the middle of it? What other country is so love-oriented?
Alola- Hawaii (If this wasn't you answer, then you either haven't played it, or are the most morinic man alive)
As I said, If you disagree, please tell me.