Any public strikes that takes place in India, do not affect the tourist areas at all. Most of the strikes if at all, are concentrated around government buildings and offices and as a tourist you should not face any difficulty in finding food and lodging places.
That being said, let me assure you that strikes are not very common and do not affect the day to day activities of people of my country. The strikes that we read about in newspapers or see on TV are generally a demonstration for the media to cover. The city or town life goes on as usual until and unless there is a curfew announced in the city, which is very extreme.
However, if you shall find yourself in midst of such a situation, you may contact the local police by dialling 100 from anywhere in the country and seek for any kind of help or guidance you require. Better than this would be to have a local contact in the places you visit, which could be anyone from your hotel receptionist to cab driver. They will be more than happy to guide you in extreme situations.
But believe me, that would be very rare. I guess you can just relax on this and start working out on your itinerary.
Have a fun trip!!! :)