The reserves had risen USD 1.43 billion to USD 278.6 billion in the previous reporting week.
FCAs, a major component of forex reserves, rose by USD 211.7 million to USD 251.561 billion, it said.
The assets, expressed in US dollar terms, include the effect of appreciation or depreciation of non-US currencies, such as the euro, pound and yen, held in the reserves.
During the week, gold reserves remained unchanged at USD 20.747 billion, the central bank said.
For the week under review, the special drawing rights (SDRs) were down by USD 3.9 million to USD 4.394 billion, while the country's reserve position with the International Monetary Fund (IMF) fell by USD 2 million to USD 2.105 billion, the RBI data showed.