Infernape in Pokemon X and Y?

No one knows which pokemon are gonna be intially available in X and Y, as very little info has been released so far. However, you will obviously get to a point in the game (post-Elite Four) where you can transfer pokemon from other generations to X and Y, including Infernape. Not all gen 4 (or any gen other than 6) pokemon will be available at first, I assume. However, it seems that Magikarp, Gyarados, Meinfoo, and Dratini (and its evolutions) will be available intitally, since screenshots of them have been released.

So don't worry, you will be able to use your Infernape in gen 6. You'll probably just have to beat the main story first.

It is unknown as to which Pokemon are returning to Pokemon X & Y as of yet, (the game was only announced a few days ago after all,) however, I doubt that Chimchar / Infernape will be obtainable in X & Y, (unless you trade from another game of course,) because Chimchar is a starter Pokemon and they have yet to make a game where you can obtain stating Pokemon in the wild. There is a chance that other trainers will have a Pokemon from the Chimchar evolution line, but since the starters for X & Y have already been announced, they [probably] won't make a Chimchar available in game. (But there hasn't been much news about Pokemon X & Y as of yet, so it's hard to say really.)

*Also note that you can obtain all the Pokemon in X & Y, but you need to trade a lot of Pokemon over from other games to do so.

Taking a wild guess, you'll be able to get it from an NPC in the game, but you'll have to beat the Elite Four and probably do some other stuff first.

In general expect the Pokemon obtainable in the wild to be a mixture of those from all previous generations plus the new ones. I don't think they'll do another all-new-Pokemon game like Black and White where.

it is said that all generation pokemon will be included maybe not infernape but most likely chimchar

It's likely Cynthia shows up post-game with the Sinnoh starters, like Steven did in Heart Gold/Soul Silver. And I am unsure if fourth-gen Pokemon help populate PokeEurope.

To my knowledge, multiple old Pokémon are going to appear, Caterpie, Pidgey, the like. However, as to whether or not Chimchar returns...I suppose that's all up to Game Freak. If it doesn't, you can always send it into the Pokemon Bank

No, Infernape is too powerful to be in the game

I think all pokemon will make a return

No one know because information about the pokemon in the game are unknown

We don't have enough info yet on it.