Suppose that you invest INR 500 every month. In a given month, if the Net Asset Value (NAV) of your fund is INR 50 per unit, you will be able to accumulate only 10 units. In another month, if the NAV goes down by INR 10 per unit, you will be able to gather 12.5 units for the same price. If you were to calculate the average price per unit, it would come close to INR 45 per unit. This concept is called the Rupee Cost Averaging.
It is important to remember here that Rupee Cost Averaging is not a guaranteed way to make more money or eliminate risks. By staying invested irrespective of market conditions, you may be able to accumulate wealth over the long-term.