WHAT IS AN FIR ?
A First Information Report (FIR) is a written document prepared by the police when they receive information about the commission of a cognizable offence. It is the first step in initiating a criminal investigation.
The Section 154 of the CrPC, 1973 governs the registration of FIRs. It applies only to cognizable offences those in which the police have authority to arrest without a warrant and begin investigation without prior approval of a magistrate (e.g., murder, rape, robbery, etc.) Filing an FIR is the first step in initiating an investigation by the police into a cognizable offense.

1.Who Can File an FIR?
Any person who has knowledge about the commission of a cognizable offense, whether a victim, witness, or someone with knowledge of the crime. A police officer can file it suo motu (on their own) if they witness or discover a cognizable offence.

2.Where Can It Be Filed?
An FIR can be filed at any police station. The fact that the crime may not have been committed in that police stations jurisdiction has no consequence to the filing of the complaint. It is mandatory for the police to record the information provided, and then transfer it to the police station in whose area/jurisdiction the offence took place. For instance, if a crime was committed in North Delhi, the information can even be registered with a police station in South Delhi.
This concept is generally referred to as “Zero FIR” and was introduced in 2013. Before the introduction of Zero FIR, massive delays were caused because the police station would record the information only in the area where the crime occurred.

3.Mode of Giving Information:
-Oral Information:When information about a cognizable offense is given orally to the police, they must record it in writing. The police officer will ask the informant to narrate the details, and then write it down in plain language, as close to the informant's words as possible.
-Written Information: Information can also be given in writing to the police, either by submitting a written complaint or by giving a handwritten document.
Regardless of the mode of information provided, the police officer must write down the information, read it back to the informant, and have the informant sign it. The police must also record the date and contents of the FIR in the police station diary.
Legal Effects of Filing an FIR

1. Commencement of Investigation

The registration of an FIR gives the police the authority to:
(a)Visit the crime scene.
(b)Collect evidence and interrogate witnesses.
(c)Arrest the accused without warrant (in cognizable offences).

2. Not Substantive Evidence
Although an FIR is an important document, it is not substantive evidence. It can be used:
To corroborate or contradict the testimony of the informant (under the Indian Evidence Act)
3. Grounds for Arrest and Trial
The FIR forms the basis for police action and ultimately the filing of a charge sheet under Section 173 CrPC, which initiates the trial process.

4. Right of the Accused
The accused can obtain a copy of the FIR.The accused can challenge a false or frivolous FIR through a writ petition or a petition under Section 482 CrPC before the High Court.

Conclusion
The First Information Report (FIR) is a vital procedural document that plays a foundational role in criminal investigations. While it is not evidence by itself, its importance lies in triggering the criminal process and providing a record of the complainant’s version of the events. Given its power to affect the liberty and reputation of individuals, safeguards such as judicial oversight and provisions for quashing are essential to prevent misuse. A clear understanding of the FIR process is crucial for ensuring both accountability and protection of rights in the criminal justice system.