Defamation on social media.

What is specific incident for filing a complaint u/s 499 / 500 IPC before area Magistrate, however, police has no jurisdiction for case of defamation.

The duty of victim is making a complaint to police, and depending on such investigation it is the duty of the police to register the FIR.  Filing a complaint with prima facie evidence is not a crime.  Making false allegations without any basis is only a crime..  The facts are to be stated in a complaint to Police.

The Madras High Court has ruled that a complaint of criminal defamation cannot be made directly to the police and that the latter has no authority to register a First Information Report (FIR) on the basis of such a complaint unless there was a specific direction from a judicial magistrate under Section 200 of Code of Criminal Procedure (Cr.P.C.).