What is approx margin required to sale currency option?

Zerodha span calculator not showing me how much initial & exposure margin when i m selecting sale option for currency ?

If i sale Nifty option 1 lot=75 shares , I requaired Rs.42000/- Approx. I think it is around 7% of whole contract value 75 x 8000 = 600000

So if I am sale 1 lot USDINR option 66.50 @ 0. 4650 then how much margin i need to pay ?

Omkar, checking why it is not working.

Margin required will be around Rs 1400 (2.5 to 3%)

66.50 is In the money so not showing me span & exposure …but when iI am entered 67.75 ATM & 67 OTM 67.25 OTM …it show me both margin so there is no need to pay margin when we sale ITM Option. ? Calculator show me NA NA NA
(Current RATE 66.84)