Structure of ISI
1. Joint Intelligence X (JIX)
It serves as the secretariat which co-ordinates and provides administrative support to the other ISI wings and field organizations. It also prepares intelligence estimates and threat assessments. It provides administrative support to the other major divisions and regional organizations of the ISI.
2. Joint Intelligence Bureau (JIB)
One of the largest and most powerful divisions of the ISI, monitors political intelligence. The JIB consists of three subsections, with one subsection devoted to operations involving India, other operations involve, anti-terrorism and VIP security.
3. Joint Counter Intelligence Bureau (JCIB)
Responsible for oversees intelligence operations in Central Asia South Asia, Afghanistan, the Middle East, Israel and Russia also responsible for field surveillance of Pakistani diplomats stationed abroad, if need be monitoring foreign diplomats as well .
4. Joint Intelligence/North (JIN)
Conduct ISI operations for Jammu and Kashmir , including monitoring Indian forces deployed within disputed Kashmir forcefully held by India.
5. Joint Intelligence Miscellaneous (JIM)
Responsible for covert offensive intelligence operations and war time espionage.
6. Joint Signal Intelligence Bureau (JSIB)
It includes Deputy Directors for Wireless, Monitoring and Photos, operates a chain of signals intelligence collection stations, and provide communication support to its operatives. It also collects Intelligence through monitoring of communications channels of neighboring countries. It has a chain of stations that track and collect intelligence signals along the Indo-Pakistani border and in Kashmir.
A sizeable number of the staff is from the Army Signal Corps. It is believed that it has its units deployed in Islamabad, Quetta, Karachi, Lahore and Peshawar.
7. Joint Intelligence Technical Division (JIT)
Not much is know about this section however it is believed that JTI/JIT include a separate explosives section and a chemical warfare section.
The ISI maintains one more primary sections in addition to the seven outlined above that is the Joint division of technical Intelligence.
Source: ISI Pakistan