Does it make difference in SE Rankings if u have a .com or any other country top level TLD like .us .cc .pk .in . Will Search engine prefer a specific country TLD over the other ?

any one ???

With a country specific tld you may appear in the Google results for pages from that country.

For example with a .ie domain, your site will be ranked in the "Pages from Ireland" results

If you are doing business primarily in 1 country, get the country specific tld. If you are doing business outside your country, get the .com. Actually, I'd advise to get both if they are available and redirect one to the other.

I believe extension plays a small part in ratings, if you can get both, do it. Google does rank things different based on which portal you come in on (google.com or google.countryTLD). I just did a quick look over it and it seems to play a minor difference.

in case you're wondering what I tested you can see if you get the same results with my test:
my query: nepalnews
i tried it on google.com and google.com.np
result was nepalnews.us was rank 6 on .com and 7 on .com.np

so it seems extension would play a role in ranking.