Hi Nikita,
Thanks for contacting Syncfusion support.
SfDataGrid is not a cell oriented control. It is data bound grid control. So it is not possible to directly get a cell and set a value for the cell as you mentioned. However, you can set value for a cell using the row and column index by using the this.SfDataGrid.View.GetPropertyAccessProvider(). Please refer the below given help documentation.
Please let us know if you require any other assistance from us.
Regards,
Mohanram A.