If you click the Amazon link I gave, you will see that the replacement is an original lamp supplied by Optoma.Thanks for spending some time and replying to me.
I am looking for first-hand information. I did search Google. I did found lamp at Amazon.com. As per the reviews, there are bad quality lamps out there (even at Amazon). I am trying to find lamp in India as of now.
You can also go to this site- OptomaUSA Online Store -- Lamps, Pico Accessories, Projectors, Accessories