The heart-breaking loss in the campaign opener has dented their chances of moving ahead after they let in two goals in the last eight minutes in Guwahati on September 5.
Qatar, ranked 62nd in the world, will start Tuesday's Group E match against 103rd ranked India as overwhelming favourites.
"We are, however, looking forward to it...there will be a fight, no matter who we play. We have to make sure we don't repeat the small mistakes that cost us three points (against Oman)," Chhetri said.
India team coach Stimac said it's an opportunity to learn.
"Qatar are the strongest team in the group and playing them will not be easy. However, it's a great opportunity to learn from. We have to change 4-5 players. There is no reason to fear and we shall look to score goals and play good football," Stimac said.