Important points for mcqs are here as under .

SAARC
• Secretariat: Kathmandu, Nepal
• Official languages: English
• Establishment: December 8, 1985
• SAARC Secretariat was established in Kathmandu on 16 January 1987
• Members: (8) Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka
• Observers: (9) China, US, Australia, EU, Iran, Japan, Mauritius, Myanmar & South Korea
• Chairman: Mohammed Waheed Hassan Manik
• Secretary-General: Ahmed Saleem

ASEAN
• Secretariat: Jakarta, Indonesia
• Official languages: English
• Secretary-General: Surin Pitsuwan
Establishment
• Bangkok Declaration: 8 August 1967
• Charter signed on: 16 December 2008
• Members: (10) Indonesia, Malaysia, Philippines, Singapore , Thailand, Brunei, Burma (Myanmar), Cambodia, Laos, and Vietnam.

OIC
• Secretariat: Jeddah, Saudi Arabia
• Official languages: Arabic, English, French
• Establishment: September 25, 1969
• Secretary-General: Ekmeleddin İhsanoğlu (Turkish)
• Members: 57 member states
• It changed its name from the Organisation of the Islamic Conference on 28 June 2011 and renamed as Organisation of Islamic Cooperation

ECO
• Secretariat: Tehran, Iran
• Official languages: English
• Establishment: 1985
• successor organisation of Regional Cooperation for Development (RCD), founded in 1964, which ended activities in 1979.
• Secretary-General: Shamil Aleskerov
• Members: 10 member states Iran, Pakistan, Turkey Afghanistan, Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan.

SCO
• Secretariat: Beijing, China
• Official languages: Chinese and Russian
• Establishment: 2001
• Secretary-General: Muratbek Sansyzbayevich Imanaliyev
• Members: (6 Members) China, Russia, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan
• successor organization Shanghai Five, founded in 1996; after the inclusion of Uzbekistan in 2001, the members renamed the organization.
• Observers: (5 )Pakistan, India, Iran, Afghanistan and Mongolia