because it is monthly expiry. NIFTY MAR 14300 CE is the 25th March option contract. Since the monthly expiry is on 25th March, the monthly expiry contract will also be the weekly expiry for the trading week from 19th to 25th.
Then how can we trade 25th March options contract s
As 25th March is monthly expiry, there won’t be seperate weekly expiry options. These will act as both weekly and monthly expiry. You can just add for example (NIFTY MAR 15000 CE) to marketwatch and trade.