I am following http://jsfiddle.net/gh/get/jquery/1.7.2/highslide-software/highcharts.com/tree/master/samples/highcharts/drilldown/async/ Link for making Drilldown chart.
Below is the working code with ajax for drilldown levels:
Create ajax_response.php with below codes:
'Cars', 'data'=>array(array('Toyota', 1), array('Volkswagen', 2), array('Opel', 5)));
}else if($_REQUEST['name'] == "Fruits"){
$response = array('name' => 'Fruits', 'data'=>array(array('Apples', 5), array('Oranges', 7), array('Bananas', 2)));
}else if($_REQUEST['name'] == "Animals"){
$response = array('name' => 'Animals', 'data'=>array(array('Cows', 2), array('Sheep', 3)));
}
echo json_encode($response);
?>