Hi Alex,
Thanks for using Syncfusion product.
You can get the select cells and selected ranges in the spreadsheet control by using the SelectedCells and SelectedRanges property in GridModel as show in the following code snippet.
[C#]
var selectedcell = Spreadsheet.GridProperties.ActiveSpreadsheetGrid.Model.SelectedCells;
var selectedrange = Spreadsheet.GridProperties.ActiveSpreadsheetGrid.Model.SelectedRanges;
Please let us know if you have any queries.
Regards,
Ponraja