The rise in consumer prices was slightly lower than the 6.84 percent seen in February, the statistics agency said.
Prices fell 0.32 percent month on month, compared with an increase of 0.13 percent in February.
"This is the highest monthly deflation in four years," the agency's chairman Rusman Heriawan told Dow Jones Newswires.
However, annualised core inflation, which excludes volatile food prices, accelerated to 4.45 percent in March from 4.36 percent in February, suggesting prices would likely rise further in the coming months.
The figures come after Bank Indonesia in February raised interest rates 25 basis points to 6.75 percent in a bid to rein in inflation, which last year hit almost seven percent after extreme weather disrupted harvests.