I think you meant
{"XXXX":
{"type":"RSS","value":"},
"YYYY (mins)":{"type":"String","value":""},
"ZZZZ":{"type":"String","value":""}
is the JSON you get from server. You can always get the JSONObject.toString and edit it as required and then do something like,
JSONObject obj = new JSONObject(myString);
If you need to add a key value to JSON you may try,
JSONObject value = new JSONObject();
value.put("key","value");
value.put("key","value");//add all the field you want for ZZZZ.
obj.put("ZZZZ",value);