Limit datatables fields

I am using AJAX to source my datatables data. However, I am getting the error:

unknown parameter '0' for row 0, column 0

because my ajax response object has more fields than what I defined in my table's initialization. Is there a way I can limit or specify what parts of the ajax response go into my datatable? Here's my javascript:

$.ajax({
    type: "GET",
    url: "/api/admin/employees",
    success: function(data) {
        $('#eployees').DataTable({
                responsive: true,
                data: data,
                columns: [
                    { title: "Name" },
                    { title: "Position" },
                    { title: "Office" },
                    { title: "Extn." },
                    { title: "Start date" },
                    { title: "Salary" }
                ]
        });
    },
    error: function(data, status, res) {
        console.log('error...');
        console.log(res);
    }
});

Note - my data object contains 20 fields, but I only need the 6 that are defined below.

Can someone help? Thanks in advance!