Digging into data released by the central bank on the issue of different notes and coins offers some clues
India has a problem with small change. It is rather common that autorickshaw or taxi fares are rounded up to the nearest multiple of 10 because the driver cannot find the change. It is common to buy additional items on a visit to the neighbourhood store so that your bill ends up as a round number. In restaurants, it is common for tips to be a function of rounding up the total bill to the nearest conveniently-payable number. A popular joke is that toffees will soon be a legal tender as they are frequently handed out by shopkeepers in lieu of small change.