Totally agree in principle. I don’t know about India, but geothermal is not feasible in many places on Earth, same goes for hydro (and with climate change, hydro has become increasingly unreliable in mountain areas due to the lack of snowfall). Wind usually doesn’t do much at night and in winter, so it’s not much help to solar in that regard.
So yeah, nuclear and batteries will have to work together to fully decarbonize our economies. Unfortunately greenfield nuclear is dead in the water almost everywhere for political reasons; even just keeping existing nuclear reactors running has been a losing battle here in Europe. Maybe Chinese designs will power India, I’m not up-to-date on the latest developments there.