Hello Vivek,

You can put logic in the RowSelectionChanging client side event to achieve the required. This logic needs to cancel the default behavior, if the RowSelectionChanging is triggered by selecting the checkbox, and then manually remove/add rows to the selected rows collection:

This is how you attach to the event:

This is the event handler:

function WebDataGrid1_Selection_RowSelectionChanging(sender, eventArgs)
{

// following if statement determines if a checkbox has been clicked, because it is not a real checkbox, but an IMG element
    if (event.target.tagName === "IMG") {
        eventArgs.set_cancel(true);
        var newRow = eventArgs.getNewSelectedRows().getRow(0);
        var lastRow = eventArgs.getCurrentSelectedRows().getRow(0);
        // deselect last row
        sender.get_behaviors().get_selection().get_selectedRows().remove(lastRow);
        // Select row
        sender.get_behaviors().get_selection().get_selectedRows().add(newRow);
    }
}

Please let me know if you have further questions, I will be glad to help.