Ah, you're in India. I don't know what's available or not over there.
Honestly, if you're "only" gaming then there's no real point in getting the X6 - until games use more than 4 cores you won't see any benefit, and in some cases (such as Formula 1 2010) the X6 will perform WORSE than a X4 because of some issue recognising the additional cores.
Also, the X4 965BE is cheaper than the i5 200K (my price comparison was between the i5 and the X6).
If you're going to make use of the extra 2 cores, such as with video encoding, then yes go with the X6 if you can't get the Sandy Bridge.
If ultimately you do go with the X4, you might be better off getting a better graphics card with the money saved - the 6870 is a good card, but the 6950 is better (and the 1GB version performs almost identically to the 2GB version, so it's not much more expensive than a 6870).