There is no strike found for any Bank Nifty option for BANKNIFTY28SEP17xxxxCE or PE? However I can find instrument for BANKNIFTY17SEPFUT? In NSE Option chain I can find strike for expire 28SEP17 for BANK NIFTY, Is something missing in zerodha instrument list?
28 SEP 17 is monthly options for which the symbol format is BANKNIFTY17SEPxxxxxCE where xxxxxxxx is strike.