Mumbai, Aug. 19 -- The Indian rupee appreciated 40 paise to close at 86.99 (provisional) against the US dollar on Tuesday, supported by optimism over GST restructuring and positive domestic equity markets. Indian shares rose modestly on Tuesday, extending gains from the previous session amid hopes that Prime Minister Modi's recent GST reforms will potentially ease inflation and pave the way for further rate cuts by the Reserve Bank of India (RBI). Investor sentiment was also underpinned by renewed diplomatic efforts aimed at ending the war in Ukraine and improving Sino-India relations amidst global uncertainty. The benchmark BSE Sensex rose 370.64 points, or 0.46 percent, to 81,644.39 while the broader NSE Nifty index closed up 103.70 poi...