tedster - 6:49 pm on Oct 21, 2010 (gmt 0)
Aji, this kind of ranking *should be* a natural result of the way Google handles ccTLDs. Are these three domains publishing the same content? (I assume so)
Each domain will need its own independent backlink profile, and ranking will most likely be harder for the .com than the ccTLDs.
Recently there have been some odd and unstable changes in geolocated search results. Whatever that is all about (and it really isn't clear to me so far) might also have some effect in your scenario - with the .com ranking better than expected in UK or India, for instance.
Still, if the same content is available on the ccTLD for a country, I would expect the .com to be filtered out of that country's results.