I am coming to Pondicherry in December for a month and I am currently searching guest house or budget hotel where I can stay comfortably for a month. I am not looking for any specific location, but it should be near to the beach and restaurants.
How much are you willing to spend per day on accommodation? Your duration is fairly long and renting a room at someone's house would work out a lot cheaper is you just need the room for sleeping at night it is not a bad option in my view.
It would be good if you gave some indication on costs, there are so many hotels which range from as low as Rs700 a night to Rs4000 a night. With some idea on costs hotels recommendations can be narrowed down to your needs.