India is a union of states and Union Territories. For the
purpose of administration, India is divided in to the national
capital territory of Delhi, 28 states and 6 centrally
administered union territories.
In 1950, the Indian constitution took effect the office of the Governor-General was abolished, and India created several different categories of states.
Between 26 Jan 1950 and 1st November 1956 there were four types of divisions part A (under a Governor) Part B (under a Rajpramukh ) , part C (under a Chief Commissioner) and one part D territory, from 1956 there were only states former (Part A and B states) and Union Territories (former Part C and D territories). Gaps in the lists of chief ministers usually signify periods of “President’s rule”.
In 1953, The Telgu-speaking portion of Madras state voted to become the new state of Andhra Pradesh, the first of India’s linguistic states.
In 1956, when the states Re-organization Act took effect, the distinction between part A, B and C states was gone, and instead state boundaries were drawn along linguistic lines. The new states, mostly the former Part A states , were Assam West Bengal, Bihar, Maharashtra, Gujarat, Kerala, MP, Madras, Mysore, Odisha , Punjab, Rajasthan and UP. Delhi, Himachal Pradesh, Manipur, Tripura, Pondicherry, Andaman and Nicobar Islands and the Laccadive, Minicoy, and Amandivi Islands become Union territories. The reminders of the states were merged into the new states of UTs.
Several new states and UTs were created out of existing states since 1956, Haryana was created in 1966 out of Punjab. The UTs of Arunachal Pradesh, Meghalaya, Mizoram and Nagaland were created out of Assam.
In 2000 Three new states were created; Jharkhand from Bihar, Chhattisgarh from MP, and Uttarakhand from UP. The Kingdom of Sikkim was annexed to India as a state in 1975. In addition, several Union Territories have become states namely Goa, Arunachal Pradesh, Meghalaya, Mizoram and Nagaland.