India Calculating Gross Margin% and Net Margin %

[Rituparna Duttagupta]

Hello, I need help in calculating the Gross Margin % of an Indian company. For calculating gross profit, should we take total revenue or revenue from operations? Further, how should I calculate COGS ,I have the following figures at hand -
Cost of materials consumed
Purchase of stock in trade
Operating and direct expenses
Changes in inventory of FG, WIP and stock in trade
Employee benefit expenses?
Please help.