This document provides a concise overview of the procedures and powers related to inspection, inquiry, and investigation of companies under the Companies Act. It details the Registrar's powers to call for information, the conduct of inspections and inquiries, search and seizure provisions, and the establishment and functions of the Serious Fraud Investigation Office (SFIO). It also covers investigations ordered by the Tribunal, security for costs, inspector reports, and actions taken by the Central Government. This note is particularly useful for CA and CMA Final students preparing for their examinations.