FIR can be lodged with the Police Station whereas a complaint is to be made to the Magistrate.

Section 154 Criminal Procedure Code, 1973 deals with information in cognizable cases. Every information relating to the commission of a cognizable offence, if given orally to an officer in charge of a police station, shall be reduced to writing by him or under his direction, and be read over to the informant; and every such information, whether given in writing or reduced to writing as aforesaid, shall be signed by the person giving it, and the substance thereof shall be entered in a book to be kept by such officer in such form as the State Government may prescribe in this behalf. Such information is called FIR. A copy of the first information report shall be given forthwith, free of cost, to the informant. Complaint under section 2(d) of the Criminal Procedure Code means any allegation made orally or in writing to a Magistrate, with a view to his taking action under this Code that some person, whether known or unknown, has committed an offence, but it does not include a police report. However, a report made by the police officer in a case which discloses after investigation, the commission of a non-cognizable offence shall be deemed to be a complaint, and the police officer making the report as a complainant. In general a complaint into an offence can be filed by any person except in cases of offences relating to marriage, defamation and offences mentioned under Sections 195 and 197.