Quote: "So I cant use that and I would have to make my own case and get it rated by something else? "
Correct. Xplosys has pretty much said it all already. You can't have an ESRB rating on a commercial box cover that hasn't been rated by the ESRB. And as Metal Devil has pointed out, you're also using a copyrighted image that belongs to CAPCOM (Resident Evil), which is also illegal without permission from the original artist/copyright holder.
Quote: "any suggestions on any website that supply free rating system"
You can look into
TIGRS. It's free, but it doesn't carry the same recognition as an ESRB rating. But as Bullshock mentioned, before you invest all of this time working on the cover for your game, you need to finish the actual game first. A game cover is designed around the game, not the other way around.
Kravenwolf