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 a report of information that reaches the police first in point of time and that is why it is called the First Information Report.In case an FIR is filed against you, then you will immediately get arrested by the police if the offence you are charged with is cognizable.
Or if there are any chances of an FIR getting filed against you, then you go to the police station and check for your name in the register kept in the station or in the online record maintained by the police.
Since March 2016 all police station records have been interlinked and you can check if an FIR has been filed against you at the CP office.
You can also call the police station and ask about the same, they will provide with the information if FIR has been registered against you or not.
You can also file an application under Right to Information act of 2005 with same police Station to get the information about whether police has registered an FIR against you or not.
You can also find if an FIR has been registered against you from the concerned Magistrate court.
Reference: Right to Information act of 2005