The key to this question is recognising that Section 206 is designed to speed up the summary trial of petty offences, and summary trials in the CrPC scheme are conducted at the Magisterial level.
Since petty-offence procedure under Section 206 is a Magisterial function by design, the correct answer is A Magistrate only.
Another way to confirm this is to look at what the special summons actually allows the accused to do, plead guilty by post and pay a fine without appearing, and ask which court's ordinary procedure this fits.
Since the postal-plea summary procedure under Section 206 is exclusively a Magisterial mechanism, the correct answer is A Magistrate only.