This feature is now a part of Practo Ray Pro plan.

To know the daily and monthly consumption of an item, on the menu bar click on reports and Select Report Category as ‘Inventory’

Access Inventory Report

On the right, select the category “Daily Stock Consumption Item Wise”, then you select the “Item Name” from the drop down on the left, and you’ll get the daily report
Daily Stock Consumption report

Likewise you can select the the category “Monthly Stock Consumption Item Wise” for a monthly report

Monthly Stock Consumption