It has more to do with the American Dollar gaining against the Indian Rupee because the INR to NRS ratio is still pretty much stable around the 1:1.60 mark (like it has always been)..

And I am just guessing if it has anything to do with gas prices in the US...If you observe the two curves below, there certainly seems to be a trend of US dollar gaining on the Indian Rupee as the gas prices decreases ...Just my raw thought though....

US $ to INR (http://finance.yahoo.com/currency/convert?from=USD&to=INR&amt=1&t=1y)

US Gas prices (last six months) (http://www.gasbuddy.com/gb_retail_price_chart.aspx)