How do you get shini Charizard?

Answer 1

your chances without corrupting your data is 1/8192 evey time ways of getting one: 1) have a 1/8192 when starting a game such as leaf green or fire red 2) Trade with a friend 3) corupt your data and get one with a A.R (action Replay)* * there are side affects

Answer 2

I'm not 100% sure, but I think you can get one when you migrate it form fire red, or leaf green, and use a poke radar.