Hi KB,
Thank you for posting query to us.
You can use the SelectCellsMouseButtonsMask property to prevent the right button from affecting any selections.
this.gridDataBoundGrid1.Model.Options.SelectCellsMouseButtonsMask = MouseButtons.Left;
Please refer the sample and let us know if this helps.
http://websamples.syncfusion.com/samples/Grid.Windows/F67349/main.htmThank you for using Syncfusion Products.
Best Regards,
Jeba.