Hello, just follow the below :
1. Click Start > Settings > Control Panel > Regional & Language Options
2. Click Regional Options Pane Tab > Customize > Currency
3. Click Currency Symbol and type Rs. (in the box, where $ is shown)
4. Click Apply then OK again Apply and OK and close the box
5. Now open Excel file and highlight the column or rows (which u want to format in Indian Rs.)
and click Format Menu > Cells > Number > Currency > Symbol > Select Rs. symbol
Hope this works for you.