Yes. D9 works with a 100% Indian diet, whether it is South Indian, Maharashtrian, Gujarati, Bengali or another Indian cuisine.
We will mention non-Indian options but these are not necessary. It’s totally up to you. We find that most D9’ers eat a traditional Indian diet 80-90% of the time and eat non-Indian food 10-20% of the time. D9 will help you with both.