Police rules

The police should act immediately on any FIR but if there be any reason to justify the delay, it is accepted.  However, if you feel that there is an inordinate delay or no action at all taken by the police in the station, you may take up the matter with the higher police official of the district with a copy of the complaint and if you do not get proper response from the higher police official also, on a private complaint u/s 200 Cr.P.C, you may take up the matter through a magistrate court. 

If  person lodged a complaint regarding a cognizable offence the station house officer have to register the FIR and start investigation. Supreme court as passed a number of judgements about this. If the complaint regarding the non- cognizable offence the police cannot register the FIR and start investigation without the permission of the Judicial magistrate. If the police refused to register the Complaint, the complainant can send the copy of the complaint to the superintendent of police of the district or he can file the case before the Judicial Magistrate U/s 200 Cr.P.C with a prayer to direct the police cncerned to register the case and investigate the case U/s 156(3) of Cr.P.C. See Section 154 Cr.P.C to get more details.