You can use built in JSONArray and JSONObject classes

String jsonString = "[
   [
      {
         "condition_id":"1",
         "condition_name":"Type 1 Diebetics"
      }
   ],
   [
      {
         "condition_id":"2",
         "condition_name":"Type 2 dypatise"
      }
   ]
]";
JSONArray jsonArray = new JSONArray(jsonString);
for(int i=0;i<jsonArray.length(),i++) {
   JSONArray childJsonArray = jsonArray.getJSONArray(i);
   JSONObject contentJsonObject = childJsonArray.getJSONObject(0);
   String conditionID = contentJsonObject.getString('condition_id');
   String conditionName = contentJsonObject.getString('condition_name');
   Log.i("TAG","Index "+i+" condition_id "+conditionID+" condition_name "+conditionName);
}