Can I buy an Option after the strike price has crossed?

For eg. Nifty index is at 11800 pts., So can i buy a call option of Nifty 11750 strike price? Would there be any charges other than the normal brokerage, normal STT etc.?

why not , you can buy any strike price option :slight_smile:
check span page for today allowed range

@parikh.rohan18,
You can buy or sell options of all strike prices available(both in the money and out of the money).
You can start with reading about options on Varsity.