Try this..
{ ==> JSONObject
and [ ==> JSONArray
try {
JSONObject json = new JSONObject(content);
JSONArray leaders= json.getJSONArray("rows");
Log.d("leaders",leaders.toString());
for(int i=0;i<leaders.length(); i++){
JSONObject jsonas = leaders.JSONObject(i);
String fname = jsonas.getString("Fname");
Log.d("First Names",fname);
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}