India's Central Intelligence Bureau (IB) is reputed to be the oldest intelligence agency in the world. In the past it was tasked with all intelligence targeting but in recent times it has focused on internal security. The IB is officially under the Ministry of Home Affairs (MHA), but in practice the Director IB (DIB) is a member of the Joint Intelligence Committee (JIC) and Steering Committee and has the authority to brief the Prime Minister should the need arise, but intelligence inputs (at least in theory) go through the regular channels in the MHA to the JIC.
The collection mechanisms of the IB vary depending on the region, but the IB operates both at the state level and the national level. The bulk of the intelligence collection is carried out by `Grade II' employees of the IB, i.e. in increasing order of seniority; the Security Assistants (Constable), the Junior Intelligence Officers (Head Constable), the Asst. (Central) Intelligence Officer (Sub-Inspector), Deputy Central Intelligence Officers (Inspector), and Joint Central Intelligence Officers (Superintendent of Police). The `Class I'(gazette) officers carry out coordination and higher-level management the IB. These officers are (again in increasing order of seniority) Asst. Director, the Deputy Director, Joint Director, Addl. Director, Special Director or Special Secretary and finally the Director IB. Grade II officers are in part direct recruitment and officer deputed from state police forces, but Class I officers are mostly deputed from state services.
At the state level all IB officers are part of the State Special Bureau report to a Central Intelligence Officer (the intelligence advisor to the Governor). The IB maintains a large number of field units and headquarters (which are under the control of Joint or Deputy Directors). It is through these offices and the intricate process of deputation that a very `organic' linkage between the state police agencies and the IB is maintained. In addition to these at the national level the IB has several units (in some cases Subsidiary Intelligence Bureaus) to keep track of issues like terrorism, counter-intelligence, VIP security and threat assessment, and sensitive areas (i.e. J&K, North East Region (NER) etc...).