Kolkata: India's foreign exchange reserves have fallen by roughly $60 billion over the past six weeks as the Reserve Bank of India (RBI) aggressively sold dollars to prop up the rupee, one of Asia's worst-performing currencies.On October 9, the RBI's foreign exchange reserves stood at $726.027 billion, down from the lifetime high of $785.706 billion on September 4, official data showed. This fell by $8.578 billion in the reporting week, according to the RBI's weekly statistical supplement.Foreign currency assets, the largest contributor to the country's reserves, fell by $7.142 billion in that week to $597.605 billion.