I've purchased CD-Key for Call of Duty: Ghosts as a Steam gift from a 3rd party site. Can I somehow confirm that it's region free version instead of RU? If it's RU I shouldn't be able to redeem it as a gift, right? Because it's region locked.
Your only place to find information on the content that will be unlocked from a Steam key will come from the vendor that took your money. Otherwise the only option is to try to redeem it, but if your redemption succeeds the content is immediately tied to your account (and not giftable).