index Number(default: -1)

The index of the initially selected item. The index is 0 based.

Example - select second item

<input id="multicolumncombobox" />
<script>
var items = [{ text: "Item 1", value: "1" }, { text: "Item 2", value: "2" }];
$("#multicolumncombobox").kendoMultiColumnComboBox({
    dataTextField: "text",
    dataValueField: "value",
    dataSource: items,
    index: 1,
    columns: [
      { fields: "text" },
      { fields: "value" }
    ]
});
</script>