Comparing BRICS and NATO is very difficult as the BRICS bloc is still relatively small and new establishing in 2006, while NATO is large and was founded in 1949.
BRICS (Brazil, Russia, India, China and South Africa) 5 member states from South America, Africa, Asia and Eurasia was founded on principles of cooperation, trade, non-interference, equality, and mutual benefit.
While NATO (the North Atlantic Treaty Organisation) consisting of 29 member states from North America, Europe and Turkey, was founded on the principles of collective defense and security of the North Atlantic area, defending each other when needed (an attack on one NATO country is an attack on all).
Initially, NATO was established as an organisation to prevent another world war, to build trade partners and hedge against the feared communism of the time. Today it is well noted by economist that NATO has helped its member states, by boosting not only trade but their economies, education systems, innovation and entrepreneurship.
BRICS can therefore be seen as a NATO in the beginning stages per se, BRICS only being established in 2006 known then as BRIC, is an association of major emerging economies similar to NATO but with less focus on defence and military actions. Today BRICS (with the joining of South Africa) is more interested in the development of it member states in these key areas: economy, business and trade, education, agriculture, health, technology, science and trade.
BRICS countries contribute up to 23.2%, $18.6 trillion of Global GDP, the 5 countries make up over 3 billion in population numbers or 42.58% of the global population. While NATO’s population size of over 900 million people and the GDP of all NATO members combined, makes up almost $40 trillion.
So if we can use NATO as measuring stick as to where BRICS can go or how big it can become, then it is clear that BRICS is far from reaching its full potential as yet. All the five BRICS members are still classified as developing nations. While NATO is full of developed countries whom have already reach the heights of their individual peaks.