I Have heard that google is banning websites that are using orkut word in their domain name,IS THIS TRUE?? Do anybody know about the google policy regarding this concept.....
A quick search should answer your question... http://www.google.com/search?q=orkut at least 3 third party sites with "orkut" in the domain name in top 10 results. I wouldn't be surprised if google make a trademark claim on domains with orkut in them though.
Maybe they see those sort of websites as helping to promote their Orkut brand and have decided to leave them be. I 'think' if they have historically allowed these domains to exist they may lose some of their rights to claim as well.
Aye, in the USA at least, a trademark owner is supposed to enforce their rights. However I'm sure the Google legal team can successfully argue just about anything they want to!