Is there any way to choose which CS will be in game ???

I like to play Giant Earth Map from Gedemon and I want to choose which CS will be in game,is that possible and how???

Through the game menu, none that I have ever found. I believe though, you should be able to do it via simple folder change. Go into the folder with the civs and city states, remove the CS you do not want in game. You will need to leave only the amount you want in your current game.

As always in case's like this, make a back up of the folder before changes made.