Explanation:

All statements are correct.

National Commission for Scheduled Tribes (NCST)

• Formation: NCST was set up in 2004 by amending Article 338 and by inserting a new article 338A in the Constitution through the 89th Constitution Amendment Act, 2003. Hence, it is a constitutional body.

By this amendment, the erstwhile National Commission for Scheduled Castes and Scheduled Tribes was replaced by two separate Commissions namely:

• the National Commission for Scheduled Castes (NCSC), and

• the NCST

Objective: Article 338A inter-alia gives powers to the NCST to oversee the implementation of various safeguards provided to Scheduled Tribes (STs) under the Constitution or under any other law for time being in force or under any other order to the Government and to evaluate the working of such safeguards.

Composition: It consists of a Chairperson, a Vice-Chairperson and 3 other Members who are appointed by the President by warrant under his hand and seal.

• At least one member should be a woman. 

• The Chairperson, the Vice-Chairperson and the other Members hold office for a term of 3 years.

• The Chairperson has been given the rank of Union Cabinet Minister, the Vice Chairperson has the rank of a Minister of State and other Members have the rank of Secretary to the Government of India.

• The members are not eligible for appointments for more than two terms.

Hence option 4th is correct.