I am traveling to Mexico City for 6 months. What all Indian grocery I will get in Mexico City?

I am afraid it will be hard for you to find Indian groceries.
I have seen some products in grocery/wine stores named La Europea, (canned food, jars, bread, sauces, tea).
Maybe in Asian food stores like Super Kise and Mikasa, but I am not sure (they have also chinese and japanese stuff).
But ask someone to take you to the market and the supermarket, maybe you will find similar fruit and vegetables to the ones used in Indian cuisine.
Also, visit Indian restaurants and Vegetarian restaurants, the people is nice and they can tell you where they buy their food.
Good luck!

No NO! In Mexico an Indian Grocery Store sells Indians for YOU to eat. Not stuff Indians eat.