Hi Dipesh,
Thanks for contacting Syncfusion support.
To display the modified grand total values in tooltip. You need to modify values in pivot table “pivotValues” too. Meanwhile we have prepared a sample to change the row grand total value in “enginePopulated” event, and that value will be displayed in tooltip too. Kindly check the sample link below.
Please check the below screenshot. We have modified row grand total value for “Australia” to “$12” and that value displayed in tooltip.
We hope the above sample meets your requirements.
Regards,
Sivamathi.