While Lyon is primarily famous for non-vegetarian dishes (though if you eat fish, there's a traditional dish called a "quenelle" you might like to try), that doesn't mean there's a lack of vegetarian food in the city. Most restaurants will have plenty of veggie options for you. You might also want to check out La Vie Claire, an organic grocery store with an excellent produce section (though the prices here are a bit higher than they are elsewhere).
As for what to bring in your suitcase, most non-perishable items you'd be able to bring in your suitcase (e.g., rice, lentils, etc.) are reasonably priced in Lyon. I can't think of anything you'd be better of bringing from India. Enjoy Lyon!