In the reporting month, the central bank purchased $945 million, while sold $8.149 billion in the spot market, according to the data.
In September 2018, the RBI sold $31 million of the US currency in the spot market on a net basis, after it bought $1.012 billion, while selling $1.043 billion.
In October 2017, the apex bank was net buyer of US currency, after it had bought $1.910 billion, while sold $1.058 billion in the spot market.
RBI maintains that its intervention in the foreign exchange market is to curb volatility in the rupee and not to target a level of the domestic currency.
In FY18, the apex bank had net purchased $33.689 billion of US dollars from the spot market. It had bought $52.068 billion, while sold $18.379 billion.
In FY17, the RBI had bought $12.351 billion of the US dollar on a net basis.
In the forward dollar market, the outstanding net forward sales at the end of October 2018 was $2.888 billion, compared with $1.358 billion in September, according to the RBI data.