The National Commission for Backward Classes consists of a Chairman, Vice…

Concept: Part XVI of the Constitution creates parallel National Commissions for Scheduled Castes (Article 338), Scheduled Tribes (Article 338A), and Socially and Educationally Backward Classes (Article 338B). Since the 102nd Constitutional Amendment Act, 2018, each of these is a constitutional body, and each Article uses the identical composition formula: a Chairperson, a Vice-Chairperson, and a fixed number of other Members appointed by the President by warrant under his hand and seal.

Application: Article 338B(2) states that the National Commission for Backward Classes "shall consist of a Chairperson, Vice-Chairperson and three other Members." Adding these office-holders gives 1 (Chairperson) + 1 (Vice-Chairperson) + 3 (other Members) = 5 total members, so the blank is filled by "three."

Cross-check: The sister commissions confirm this is the standard constitutional formula rather than a special case — Article 338 (for the National Commission for Scheduled Castes) and Article 338A (for the National Commission for Scheduled Tribes) are both worded as "a Chairperson, Vice-Chairperson and three other Members," so all three Part XVI commissions share the same three-Member design. This also rules out the now-repealed National Commission for Backward Classes Act, 1993, which had used a different five-office structure (a Chairperson, a social scientist, two persons with knowledge of backward classes, and a Member-Secretary) that did not include any Vice-Chairperson post at all — so that older Act does not match this question's "Chairman, Vice Chairman, and ___ members" wording. Among the offered figures, only three matches the "other Members" count Article 338B(2) prescribes; four, five, and six each misstate that count.