var data = [
    {section: "Male", value: { average_age: 65, rate:  48} },
    {section: "Female", value: { average_age: 70, rate:  42} },
    {section: "Others", value: { average_age: 75, rate:  10} },
];

var options = {
    id: "chart",
    data: {
        plain: data,
        keys: {
            name: 'section',
            // Other Chart has only 1 value
            // So, you just need define 'value'
            value: 'value.rate'
        }
    }
};

var pieChart = new C9.PieChart(options);
pieChart.draw();