Hi Yogesh,
Thank you for using Syncfusion products.
We analyzed your query.Please ensure, you are overriding correct selection controller based on SfDataGrid.SelectionUnit. Please refer the below table,
SelectionUnit
| SelectionController to override
|
Row
| GridSelectionController
|
Cell or Any
| GridCellSelectionController
|
If you are facing the mentioned issue after overriding right selection controller also then please update us with sample to provide better solution.
Regards,
Muthukumar K