The logic followed here is: 

All the given options except BRICS are part of the United Nations organization but BRICS is a totally different and separate organization.

Hence, the correct answer is "BRICS".

BRICS is an acronym for the powerful grouping of the world's leading emerging market economies, namely Brazil, Russia, India, China and South Africa. The BRICS mechanism aims to promote peace, security, development, and cooperation.

• The United Nations officially came into existence on 24 October 1945.
• United Nations Day is celebrated on 24 October each year.
• The main organs of the UN are:
  1. the General Assembly
  2. the Security Council
  3. the Economic and Social Council
  4. the Trusteeship Council
  5. the International Court of Justice
  6. and the UN Secretariat
• All 6 were established in 1945 when the UN was founded.
• The General Assembly is the main deliberative, policymaking, and representative organ of the UN.

• London conference (officially named as Declaration of St James' palace) was signed on 12th June 1941.
  • This conference led to the idea of the formation of the United Nation,
• The Hague Conference, 1954 is related to the protection of cultural property in the Event of Armed Conflict.
• The Berlin Conference of 1884–1885, also known as the Congo Conference or West Africa Conference regulated European colonization and trade in Africa.