President of India

The President of India or Rashtrapati is the head of state and first citizen of India, as well as the Supreme Commander of the Indian Armed Forces. In theory, the President possesses considerable power. With few exceptions, most of the authority vested in the President is in practice exercised by the Council of Ministers, headed by the Prime Minister.
The President is elected by the elected members of the Parliament of India (Lok Sabha and Rajya Sabha) as well as of the state legislatures(Vidhan Sabhas), and serves for a term of five years. Incumbents are permitted to stand for re-election. A formula is used to allocate votes so there is a balance between the population of each state and the number of votes assembly members from a state can cast, and to give an equal balance between State Assembly members and National Parliament members. If no candidate receives a majority of votes there is a system by which losing candidates are eliminated from the contest and votes for them transferred to other candidates, until one gains a majority. The Vice-President is elected by a direct vote of all members (elected and nominated) of the Lok Sabha and Rajya Sabha.
The president of India resides in an estate in New Delhi known as the Rashtrapati Bhavan (which roughly translates as President's Abode). The presidential retreat is The Retreat in Chharabra, Shimla and Rashtrapati Nilayam (President's Place) in Hyderabad.

Qualifications required to become the President
A citizen of India who is of 35 years of age or above may be a Presidential candidate. The Presidential candidate should be qualified to become a member of the Lok Sabha and should not hold any office of profit under the government. Certain office-holders, however, are permitted to stand as Presidential candidates. These are:
 The current Vice President.
 The Governor of any State.
 A Minister of the Union or of any State.
In the event that the Vice President, a State Governor or a Minister is elected President, they are considered to have vacated their previous office on the date they begin serving as President.

State police

Each state and union territory of India has a state police force, headed by the Commissioner of Police (State) or Director General of Police (DGP). It is controlled by the Chief Minister and Home Minister of the state/union territory. The state police is responsible for maintaining law and order in townships of the state and the rural areas. States such as Tamil Nadu and Maharashtra have taken steps to get their police force trained by advanced police training schools notably the Atlanta City Police of the USA and the World Police Academy of Canada. The Tamil Nadu state police is at the forefront of advancement with the Tamil Nadu Police Academy which now is seeking university status.

Organisation
 Some state forces are organized into Police Ranges, headed by a Deputy Inspector General of Police (DIG) or Additional Commissioner of Police, who control several Police Districts.
 The Police District is the fulcrum of state police activity and each Police District of the state is headed by a Senior Assistant Commissioner of Police or Superintendent of Police (SP).
 The Police District is divided into Police Sub-Divisions and will be under the command of an Assistant Commissioner of Police or Deputy Superintendent of Police.
 The Police Sub-Division is made up of one or more Police Circles, and is under the command of an Inspector of Police often referred to as the Circle Inspector (CI).
 Under the Police Circles are the police stations, generally under the control of a Sub-Inspector (SI). As per the various Indian laws, Sub-Inspector (and above) are the only officers who can file a charge sheet in the court.
Each state police force also maintains its own armed police force (known as variously as the Provincial Armed Constabulary, Special Police and Armed Police) which is responsible for emergencies and crowd control issues. They are generally activated only on orders from the Additional Commissioner of Police, and higher-level authorities. The armed constabulary do not usually come into contact with the general public unless they are assigned to VIP duty or to maintain order during fairs, festivals, athletic events, elections, and natural disasters. They may also be sent to quell outbreaks of student or labor unrest, organized crime, and communal riots; to maintain key guard posts; and to participate in anti-terrorist operations. Depending on the type of assignment, the Armed Police force may carry only lathis or lethal weapons.

Narcotics Control Bureau

The Narcotics Control Bureau (NCB) is the chief law enforcement and intelligence agency of India responsible for fighting drug trafficking and the abuse of illegal substances.

Special Protection Group

The Special Protection Group (SPG) is the executive protection agency of the Government of India. It is responsible for the protection of the Prime Minister of India, other top officials, and their immediate families. The force was established in 1985 after the assassination of Indira Gandhi. It is one of many Indian law enforcement agencies.
The work of the Special Protection Group was more organised after the assassination of Rajiv Gandhi on May 21, 1991, (who was, at that time, not under SPG cover since his term as Prime Minister had ended). After the Rajiv Gandhi assassination, there have been no successful attempts to attack the Prime Minister or the Prime Minister's family members.
The Special Protection Group has about 3,000 personnel. Recruits are drawn from police forces as well as National Security Guards commandos, who undergo training similar to that conducted by the United States Secret Service. The officer cadre is mainly Indian Police Service (IPS) officers from various state/central cadres.
The Special Protection Group provides proximate security to protectees, including protection provided from close quarters, journey on foot, road, rail, aircraft, watercraft or any other means of transport, and includes places of functions, engagements, residence, etc. They comprise ring round teams, isolation cordons, the sterile zone, and the rostrum and access control to the person or members of his immediate family. The Special Protection Group, over a period of time, grew both in size as well as in specialisation.

Railway Protection Force

The Railway Protection Force {RPF} is responsible for law enforcement on the Indian Railways. They maintain discipline on platforms as well as travel inside trains to keep passengers secure. Railway accidents are also handled by them.

National Security Guards

The National Security Guards (NSG) is a commando unit originally created for counter-terrorism and hostage rescue missions. Raised in 1986, it is popularly known as the "Black Cats" for the uniform worn by its operators. Like most military and elite security units in India, it is media-shy and the general Indian public is largely unaware of its capabilities and operational details.
The NSG draws its members from the Indian Army and various central police units. It is India's premier counter-terror outfit and is typically deployed in situations that would be beyond the capabilities of regular police units. An NSG team with a dedicated transport aircraft is always stationed at Palam airport in New Delhi, ready to deploy in 30 minutes. The NSG has also been increasingly tasked with protection of VIPs. This role has expanded in recent years, as several politicians have come to view NSG protection as a status symbol. This has caused some concern among senior NSG officers and Home Ministry officials

National Investigation Agency

National Investigation Agency (NIA) is the central agency to combat terror in India. The agency is empowered to deal with terror related crimes across states without special permission from the states. The National Investigation Agency Bill 2008 to create the agency was moved in Parliament by Union Home Minister on 16 December 2008. The NIA was created in response to the Nov 2008 Mumbai terror attacks as need for a central agency to combat terrorism was found. It also deals with drug trafficking and currency counterfeiting.