Hi Rohan,
The SaveCellInfo does not fire because this control is not designed interactive with the textbox of grid, Whereas the default cellType ComboBox is a combination of button and a ListBox. When the MS comboBox is embedded on the grid, the interaction is only on that control and not on grid.
The other way of doing is to go for a custom cell type. You may either derive ComboBoxCellModel and ComboBoxCellRenderer or design from deriving GridDropDownCellModel and GridDropDownCellRenderer.
If you have the source then you may refer code from Essential Suite\Windows\Grid.Windows\Src\Base\DropDown\GridComboBoxCellRenderer.cs and Essential Suite\Windows\Grid.Windows\Src\Extensions\CellTypes\GridDropDownGridListControlCellRenderer.cs to create similar celltype.
ListBox is used for the dropdown and button is derived from GridCellButton (GridCellComboBoxButton.cs) and comboBox is not directly implemented.
After creating the custom celltype, it has to be registered through CellModels.Add function and then this cell type can be implemented.
Couple of samples can also be referred, that shows how SaveCellInfo is raised.
1. Syncfusion\Essential Studio\4.1.0.10\windows\Grid.Windows\Samples\CellTypes\CalendarCells(also available in earlier versions).
The saveCellInfo is raised as the value of calendar is pushed to the CellValue of the grid in the OnSaveChanges function.
2.
Refer this KB and see the onSaveChanges.
Let me know if you have any more questions.
Best regards,
Stanley