In any given month what is the approximate deviation of margin requirement due to volatility changes considering the price is constant. For example nifty with a average margin requirement of 100000.
There is nothing as average deviation in a month, it depends on stock, margin can go high even if price is going high with out any change in volatility.
How much margin should you keep aside as a buffer in case of increased margin requirement
May be keep min 10% extra but as said it depends on each scrip and each individual, also one should take care of losses if any.