It seems that starting June1st, the Gross Exposure Margin has been increased from 2% to 3% of the notional value. Can you please confirm if this is the case. If so, then your updated SPAN margin calculator is still showing Exposure margin using 2% and needs to be updated to reflect the change.
The exposure margin is 2% for ITM and ATM Index options. For options that are OTM by 10%, the exposure margin is 3%. For example, Nifty 11000 CE(Nifty spot of 10000) will be charged at 3% while 10900 CE will be charged at 2%.
For stock options, 3.5% is the exposure margin for ITM and ATM contracts. For options that are OTM by 30%, it is 5.25%