A sub-division is an administrative division of a district in India. It is headed by a sub-divisional magistrate (also known as assistant collector or assistant commissioner). A district may have multiple sub-divisions, and each of those sub-divisions may contain multiple sub-districts ( tehsils/ C.D. Blocks) and municipalities. [1] For example, in West Bengal, the Murshidabad district contains five sub-divisions (mahakumas).
In some states( Andhra Pradesh, Telangana, Tamil Nadu, Kerala) they are called Revenue Divisions.