Sorry for the confusion about grants. Rajulama is right and that's what I wanted to say. You should be one of the individuals (as PI or Co-PI) who received the grant.

Gohtalo is also right. One should not try EB2 NIW without research papers and strong recommendation letters. In my case I consulted the lawyer and explained him about my research and its merits. He reviewed my CV and asked me to get strong recommendation letters to prove my point. That is why I am willing to give a try, otherwise I wouldn't take the risk.

Buzz is also right. I know few individuals who had about 5-8 papers but had lots of citations. Their PR was approved within 3-4 months, but all them had H1B. That is why I started this thread to see if there is anyone who had OPT and successfully made their case.

So, if there is anyone out there who successfully made their case while on OPT, it will be a big encouragement to all of us.