As others have mentioned, before you send anyone but a government agency personal information (such as your passport) you should be careful to avoid scams. If you did not enter this contest before winning it, or are being asked by someone you did not previously know to provide personal information as part of claiming the prize, then this is almost certainly a scam. If you are thinking of sending an important document of yours with someone, make sure they are really someone you can trust. Do not make the decision to trust a person based on how much you have been told you have won.
According to the instructions for the W-7 form,
If you submit an original valid passport (or a certified copy from the issuing agency), you do not need to submit any other documents to
prove your “foreign status” or “identity.”
If you want a certified copy of your passport for this purpose, you need to get that from the agency that issued your passport. You were issued your passport from an agency in India, where you reside. You should ask that agency if they will certify a copy for you, instead of sending your passport to the US.