Nifty and the Rupee have been positively correlated in the past. A strong Rupee is good for the markets and a weak Rupee has seen the markets fall. In a research report by Religare Capital Markets it was shown that between 1990 and 2012, 69% of the time the quarterly movement of Sensex mimicked the movement of Indian rupee.
So keep a watch on the INR. A continued downtrend in the USDINR should spell positive news for Equities.