Mumbai, Dec. 17 -- Indian Rupee gained sharply in volatile trades against the US dollar today. INR had tested a fresh record low above 91 per US dollar but swung around rapidly and currently trades at 90.33 per US dollar, rising 60 paise on the day with the markets likely witnessing a timely intervention from the Reserve Bank of India after the sustained losses in local currency recently. INR has been one of the worst performing major currencies in the world this year. Last few sessions saw the currency topple despite weak US dollar index. Continued worries over overseas investment flows and an interest rate cut from the RBI weighed on the currency. However, Rupee can find some comfort in falling Crude oil futures. The benchmark WTI crude...