Use grid.dataitemthe grid in the selected row.
var grid = $('#grdMyGrid').data('kendoGrid');
var selectedItem = grid.dataItem(grid.select());
Updated by the OnChange (e) handler.
.OnChange(e=>e.OnChange("grdOnChange")) . , .
var selectedIndex=0;
function grdOnChange(e) {
var selectedDataItem = e != null ? e.sender.dataItem(e.sender.select()) : null;
selectedIndex=selectedDataItem.MyModelID;
}