Hi,
Thank you for your interest in Syncfusion Products.
This can be achieved by using the follwing code:
this.gridGroupingControl1.TableDescriptor.Columns[2].Appearance.AnyRecordFieldCell.CellType = "ComboBox";
this.gridGroupingControl1.TableDescriptor.Columns[2].Appearance.AnyRecordFieldCell.ChoiceList = s;
Please refer the sample in the below link:
http://websamples.syncfusion.com/samples/Grid.Windows/72221/main.htmKindly let me know if this helps.
Thanks,
Jisha