The Constitution distributes the legislative powers between the Parliament (http://parliamentofindia.nic.in/) and the State legislatures (http://goidirectory.nic.in/legis.htm#sl), as demarcated in the lists of entries in the Seventh Schedule of the Constitution. The residual powers remain with the Parliament. The centrally administered territories are called Union Territories.
As a consequence of over a century of British rule, a substantial portion of Indian law and Indian legal institutions are based on British law, the British legal system and the English language.
The President of India (http://presidentofindia.nic.in/) heads the Union Executive. The President is the nominal head of the State. The real power lies with the Union Council of Ministers (the cabinet) headed by the Prime Minister. India follows the Westminster form of Government with an elected President instead of a hereditary monarch (Articles 52 & 53).
The President is elected for a period of 5 years by an electoral college consisting of the members of the Union and State legislatures (Articles 55 & 56). A President can be re-elected any number of terms (Article 54). A Vice-President is elected for a period of 5 years by the members of the Union Legislature. The President can be impeached for violation of the Constitution (Article 61). The Vice-President can be removed by a mere resolution passed by both the Houses of the Union legislature (Articles 63-67).
The Prime Minister is the most powerful person in India. He is the head of the Council of Ministers. The President is normally bound to act on the advice of the Council of Ministers. The Prime Minister is usually the leader of the political party commanding a majority in the House of the People. During the recent past, the Prime Minister has been the leader of a coalition of political parties which together command a majority in the House of the People.
The Union Government is divided into a number of ministries each headed by a minister and further into departments with a larger number of Indian administrative officers and subordinate employees. See http://goidirectory.ni c.in for a directory of the government websites.
Source:-Guide to Indian Laws- By V. Ramakrishnan