Answer:
There is no language called 'Indian', therefore Indian people do not speak Indian (nobody does). There are many languages spoken in India at different regions.
Hindi is the national language and is spoken by a majority of the population. English is a practical choice for corporate communication. English is also widely used in written communication, again due to practicality as Indian languages have been ignored by software developers until recently.
Other examples of Indian languages would be Punjabi, Telugu, Tamil, Gujarati, Bengali and Bhojpuri, there are many more Indian languages, and a very large number of dialects.
(Indian people may get offended if you imply that they speak 'Indian'.)
Well i was looking for views about Indian Astrology not Indian Language?