India has a complex culture with vast divergence with in the culture, even an Indian wouldn’t know all the cultural values in all parts of India, but would relate and respect.
India is a densely populated country, soon expected to be world’s most populated country (I bet it is already if the census is done properly). Even though it’s the seventh largest country by area, the cities are getting crowded day by day, when you visit cities like Mumbai or Hyderabad, you can’t walk on the street without bumping into people. Personal space in India is less as a reason you might find people standing close to you when they are talking or some times might not notice physical touch (same sex).