Languages of India
In 1946, the issue of national language was a bitterly contested subject in the proceedings of the Constituent Assembly of India, specifically what should be the language in which the Constitution of India is written and the language spoken during the proceedings of Parliament and thus deserving of the epithet "national". Members belonging to the northern parts of India insisted that the Constitution be drafted in Hindi with the unofficial translation in English. This was not agreed to by the drafting Committee on the grounds that English was much better to craft the nuanced prose on constitutional subjects. The efforts to make Hindi the pre-eminent language were bitterly resisted by the members from those parts of India where Hindi was not spoken natively. Eventually, a compromise was reached with Hindi in Devanagari script to be the official language of the union but for "fifteen years from the commencement of the Constitution, the English Language shall continue to be used for all the official purposes of the Union for which it was being used immediately before such commencement".
Hindustani language
Standard Hindi, one of the official languages of India, is based on the Kharibol dialect of the Delhi region and differs from Urdu in that it is usually written in the indigenous Devanagari of India and exhibits less Persian and Arabic influence than Urdu. It has a literature of 500 years, with prose, poetry, religion and philosophy, under the Bahmani Kings and onwards. It is prevalent all over the Deccan Plateau.
Note that the term "Hindustani" has generally fallen out of common usage in modern India, except to refer to "Indian" as a nationality and a style of Indian classical music prevalent in northern India. The term used to refer to it is "Hindi" or "Urdu", depending on the religion of the speaker, and regardless of the mix of Persian or Sanskrit words used by the speaker. One could conceive of a wide spectrum of dialects and registers, with the highly Persianised Urdu at one end of the spectrum and a heavily Sanskrit-based dialect, spoken in the region around Varanasi, at the other end. In common usage in India, the term "Hindi" includes all these dialects except those at the Urdu spectrum. Thus, the different meanings of the word "Hindi" include, among others: