The Indian National Economic Survey vol 2 is just out for 2016/17, and it includes an interesting admission that the way we define urbanisation is skewing how urban we say we are. It's no small difference either. In 2011, if you use the statutory definition, India was 26% urban. "State governments determine the administrative status of a settlement. By default all settlements are rural and become urban only after the state government converts them, following a requisite legal process. While there are guidelines for classifying a settlement as urban, these are not binding on state governments."
If you go by the definition of over 400 people per sqkm it was 78%.
Is this the first step towards a more sophisticated treatment of India's growing urban areas, and the governing of what happens in them? The use of the terminology has implications for the development of policies, and determines where and how support is implemented.