Apart from margin,
THIS IS NOT HEDGING (Hedging means, irrespective of worst kind of upswing or downswing, you wont lose more than a certain amount) (hope i have read your post rightly without missing anything)
You are lucky that markets have rebound, else had market fallen below 7377, you could have lose money without any limit i.e. if market fall to 6500, yous would lose 877 points.
Beside it no matter how high market goes as such 8500 or 9500, you wont earn more than 223 points.
Hence I dont think broker will reduce margin for this pair. You will simply receive or pay MTM on daily basis, and you will need margin of 2 lot NF, i.e. 60/65/70K approx.