Firstly, the new margin rules are now applicable from September 01 and not from August 01. For another month, both the systems can exist simultaneously. From September 01, when the new margin rules take over, intraday positions can be based on SEBI prescribed margins. If the margin for Reliance is 20% then with margin of Rs.5 lakh, you can take positions up to Rs.25 lakhs. Nothing more than that. However, for delivery trades, you need to pay the full amount upfront so only shares worth Rs.5 lakhs can be bought.