I am an Indian citizen and permanent resident of the United States. I had two passports since my last name changed because of marriage, now I have lost my old passport but I do have my new passport and green card, I am traveling to India in two weeks; what should I do?
One does not generally need old passports when traveling. You have everything you need to travel between India and the US. To leave and enter the US, you need nothing more than your valid green card. To enter and leave India, you need nothing more than your valid Indian passport.
what should I do?
Bring both documents with you and enjoy your trip.
If the green card shows your former name, that is, your name before you were married, then you can bring a copy of your marriage certificate as proof of your name change.
Just use your current passport to enter/exit India, and your green card to re-enter the US.
Your old passport is irrelevant.