The Indian number grouping is different than the English number grouping. The Excel way of solving this problem is changing the number formats in Cell formats. Use a custom number format as;

With 2 decimals:

[>99999]##\,##\,##0.00;[<-99999.99]-##\,##\,##0.00;##,##0.00

Without decimals:

[>99999]##\,##\,##0;[<-99999.99]-##\,##\,##0;##,##0

Lakhs and crores with positive

[>9999999]##\,##\,##\,##0.00;[>99999]##\,##\,##0.00;##,##0.00

Lakhs and crores with negative

[<-9999999](##\,##\,##\,##0.00);[<-99999](##\,##\,##0.00);##,##0.00

You can also change the regional settings under Control Panel for permanent solution.