I would like to use Google Sheets for its convenient global access, but I really need to display numbers in Lakh and Crore (Indian style) format to avoid confusion among manager
This works in Google Sheets for sure. Should work in Excel too.
With the appropriate cells selected, navigate to:
Google Sheets : Format -> Number -> More Formats -> Custom Number Format
Excel : Format -> Cells -> Custom -> [Custom text box]
Enter one of the following and Apply:
A] For Lakhs and Crores with the Rupee symbol and decimals
[$₹][>9999999]##\,##\,##\,##0.00;[$₹][>99999]##\,##\,##0.00;[$₹]##,##0.00
B] For Lakhs and Crores with the Rupee symbol and without decimals
[$₹][>9999999]##\,##\,##\,##0;[$₹][>99999]##\,##\,##0;[$₹]##,##0
C] For Lakhs and Crores without the Rupee symbol and with decimals
[>9999999]##\,##\,##\,##0.00;[>99999]##\,##\,##0.00;##,##0.00
D] For Lakhs and Crores without both the Rupee symbol and decimals
[>9999999]##\,##\,##\,##0;[>99999]##\,##\,##0;##,##0
Edit: I've tested these on both Google Sheets and Excel. Negative numbers work as well.