In keeping its policy setting steady, the central bank also expressed concerned about the risk of a flare-up in inflation.
Although consumer inflation eased in October to 4.20 percent, below the RBI's target of 5 percent by March, prices in India have traditionally been dependent on volatile food and fuel prices. Global crude oil prices have spiked in the last week.
The RBI expressed special concern about core inflation, which remained around 5 percent in October. Patel, in a news briefing, called it of "critical importance" to monetary policy.
The RBI also cited concerns about the "high volatility" in global financial markets, and the potential spillover as the U.S. Federal Reserve gears up to raise interest rates next week.
The RBI's views on the economy, like the government's, are more optimistic than many private forecasters and at odds with bond markets, which had sent the 10-year bond yield to a 7-1/2 year low last month on anticipation of aggressive rate cuts, but up 20 bps on Wednesday.
India's economy grew by an annual 7.3 percent between July and September, the fastest for any large economy.
But some analysts warn that expansion is threatened by Modi's bank-note ban, and the RBI's decision has now injected a dose of uncertainty about its next review in February.
Some analysts welcomed the decision as a display of independent thinking from a monetary policy committee that was constituted this year to make decision-making more transparent and less dependent on the RBI governor.
But others said the RBI's decision aligned with the government's insistence that the impact from its action would only have a temporary impact.
Data from last month was discouraging, showing auto sales plunged and service sector activity contracted.
"The RBI seems to be a little inconsistent in the different things it is trying to say," said Varun Khandelwal, managing director of Bullero Capital.
"It is difficult to say at this point whether there will be a rate cut in the next policy meet."