Union and its territories

Article 1 

In the Constitution states that India, that is Bharat, shall be a Union of States. The territory of India shall consist of: The territories of the states, The Union territories and Any territory that may be acquired.

The names of the States and the Unions have been described in the First Schedule. This schedule also holds that there are four Categories of State and territories - Part A, Part B, Part C and Part D. 

Part A - includes the nine provinces which were under British India

Part B - princely states consisted of this category

Part C - centrally administered five states

Part D - Andaman and Nicobar Islands

In the seventh amendment of the Constitution in 1956 the distinction between the Part A and Part B states was abolished. Subsequently states were reorganized on linguistic basis. As a result several new states were formed, eg. Haryana, Goa, Nagaland, Mizoram etc. At present there are 28 States and 7 union territories.

The State

Andhra Pradesh

Arunachal Pradesh

Assam

Bihar

Chattisgarh

Goa

Gujarat

Haryana

Himachal Pradesh

Jharkhand

Jammu and Kashmir

Karnataka

Kerala

Maharastra

Madhya Pradesh

Manipur

Meghalaya

Mizoram

Nagaland

Orissa

Punjab

Rajasthan

Sikkim

Tamil Nadu

Tripura

Uttar Pradesh

Uttrakhand

West Bengal

Union Territories

Andaman and Nicobar Islands

Chandigarh

Dadar and Nagar Haveli

Daman and Diu

Delhi

Lakshwadeep

Pondicherry

Article 2 

This states that the parliament may, by law, admit new states into Union of India or establish new states on terms and conditions its deems fit.  For eg. the addition of the State of Sikkim by the 35th (1974) and 36th (1975) constitutional amendments. 

Article 3

This article empowers the parliament to form a new state by separation of a part of territory of an established state or to unite two or more states or parts of states or by uniting any territory to a part of any state. This article provides that area of any state can reduced or increased and alter the boundaries or change the name of a state. Even the though the state boundaries are subject to change, their area cannot be acquired by a foreign state.There is also a saving clause in the article to protect the rights of the state. The first condition is that no bill for the purpose can be introduced in the either house except on recommendation of the President of India. Second, whether the proposal contains the alternation of the area, boundaries or name of the state mentioned, it has to referred by President to the Legislatures of concerned states, for expressing opinions. Such opinion has to be expressed withing a period specified by the President. In any case, the views expressed do not bind the decisions of either the President or the Parliament. 

Article4

This article specifies that the laws provided in article 2 and 3, admission/establishment of new states and alternation of names , areas and boundaries etc. of established states, are not to be considered amendments of the Constitution under article 368, which means these can be passed without resorting to any special procedure and by simple majority.