JULY-AUG Options are not in instrument list...

exchange,exchange_token,expiry,instrument_token,instrument_type,last_price,lot_size,name,segment,strike,tick_size,tradingsymbol
...
NFO,45943,2021-06-24,11761410,PE,0.0,75,NIFTY,NFO-OPT,8500.0,0.05,NIFTY21JUN8500PE
NFO,45945,2021-06-24,11761922,PE,0.0,75,NIFTY,NFO-OPT,8600.0,0.05,NIFTY21JUN8600PE
NFO,45949,2021-06-24,11762946,PE,0.0,75,NIFTY,NFO-OPT,8700.0,0.05,NIFTY21JUN8700PE
NFO,45951,2021-06-24,11763458,PE,0.0,75,NIFTY,NFO-OPT,8800.0,0.05,NIFTY21JUN8800PE
NFO,45957,2021-06-24,11764994,PE,0.0,75,NIFTY,NFO-OPT,9000.0,0.05,NIFTY21JUN9000PE
NFO,45961,2021-06-24,11766018,PE,0.0,75,NIFTY,NFO-OPT,9100.0,0.05,NIFTY21JUN9100PE
NFO,45963,2021-06-24,11766530,PE,0.0,75,NIFTY,NFO-OPT,9200.0,0.05,NIFTY21JUN9200PE
NFO,45971,2021-06-24,11768578,PE,0.0,75,NIFTY,NFO-OPT,9500.0,0.05,NIFTY21JUN9500PE
NFO,45975,2021-06-24,11769602,PE,0.0,75,NIFTY,NFO-OPT,9700.0,0.05,NIFTY21JUN9700PE
...
NFO,47823,2021-06-10,12242690,CE,0.0,75,NIFTY,NFO-OPT,16350.0,0.05,NIFTY2161016350CE
NFO,47824,2021-06-10,12242946,PE,0.0,75,NIFTY,NFO-OPT,16350.0,0.05,NIFTY2161016350PE
....
NFO,48760,2021-09-30,12482562,PE,0.0,75,NIFTY,NFO-OPT,10500.0,0.05,NIFTY21SEP10500PE
NFO,48761,2021-09-30,12482818,CE,0.0,75,NIFTY,NFO-OPT,11000.0,0.05,NIFTY21SEP11000CE
....

Any idea why NIFTY21JUL16000PE (or similar "tradingsymbol") are not in the list?

if I try and look up expiry with date 2021-07-29 --> nothing.

filtering for lot size 75 gives previous month options... .but filtering for lot size 50 --> gives nothing.

do I have to look at some other file/list to get the current month expiry options ?

Current list of expiry in the file (for name==NIFTY) is below... July expiry is not there...

['2021-04-29' '2021-04-15' '2021-04-22' '2021-05-27' '2021-05-06'
'2021-05-12' '2021-05-20' '2021-06-24' '2021-06-03' '2021-06-10'
'2021-09-30' '2021-12-30' '2022-03-31' '2022-06-30' '2022-12-29'
'2023-06-29' '2023-12-28' '2024-06-27' '2024-12-26' '2025-06-26'
'2025-12-24']

Any help / guidance appreciated.