Which is an extra-Constitutional body ?

An extra-Constitutional body is an organization or agency that is not mentioned or authorized by a country's constitution. In India, these bodies are established by laws passed by the Parliament or by executive orders, rather than by constitutional provisions.

For example, the NITI Aayog is an extra-Constitutional body in India. It was created by a resolution of the Union Cabinet in 2015 to replace the Planning Commission. Unlike constitutional bodies such as the Election Commission or the Union Public Service Commission, NITI Aayog does not derive its authority from the Constitution.