Where can i file defamation case? Which place to file it?

You may file criminal compliant for defamation, as well as suit for damages, for defamation, though any such action shall depend on the fact, that allegations made against you were proven false before the court, and reference to the same is mentioned in the order favouring you.

If those allegations have been put in before public, even when those were proven false, then yes you may have a case of defamation.

You may file the complaint where cause of action has fully or partly occurred. Since the place where court cases were filed against you, definitely may be place for filing defamation complaint.