Is this a clipless pedal? I have bough a 2nd handed road bike recently. The seller said that the pedal could work as both platform pedal and clipless pedal.

Is it true? If yes, which system of clipless shoes can it work with?
Either the seller meant clipped pedal-as in you could bolt toe clips to it-or he didn't know what he was talking about. Those are not clipless pedals. They are VP road pedals that have an integrated toeclip: