Comment on Open Interest, MaxPain & Put Call Ratio(PCR)
Have you seen our new margin calculator tool on WEB?
Click for futures and SPAN, there is a small section on top of the futures page which explains all your query.
Coming back to the SPAN calculator tool, total margin is what is required to trade futures for overnight and 40% of this is required if you wish to trade intraday using product type as MIS.
Hope this helps,
Cheers,