Delhi is divided in Eleven Revenue District. Each district is headed by a Deputy Commissioner, who has under him an Additional District Magistrate, Sub Divisional Magistrates, Tehsildars and Sub-Registrar. The District Administration carries out diverse variety of functions including magisterial matters, revenue courts, issue of various statutory documents, registration of property, conduct of elections, relief & rehabilitations, land acquisition and various other areas which are too numerous to be numerated. The District Administration in Delhi is the de-facto enforcement department for all kinds of Government Policies and exercises supervisory powers over numerous other functionaries of the Government. At the apex of revenue hierarchy is the Divisional Commissioner who is also the District Magistrate of Delhi and Inspector General of Registration. He is also designated as Secretary (Revenue) and Collector under various Revenue Acts.
For more details:- http://districts.delhigovt.nic.in/