code: public boolean modifyMFSIP(String frequency, int day, int instalments, double amount, String status, String sipId) throws KiteException, IOException, JSONException {
          Map<String, Object> params = new HashMap<String, Object>();
          params.put("frequency", frequency);
          params.put("day", day);
          params.put("instalments", instalments);
          params.put("amount", amount);
          params.put("status", status);
  
          new KiteRequestHandler(proxy).putRequest(routes.get("mutualfunds.sips.modify").replace(":sip_id", sipId), params, apiKey, accessToken);
          return true;
      }
docs: Modify a mutualfunds sip.
  @param frequency weekly, monthly, or quarterly.
  @param status Pause or unpause an SIP (active or paused).
  @param amount Amount worth of units to purchase. It should be equal to or greated than minimum_additional_purchase_amount and in multiple of purchase_amount_multiplier in the instrument master.
  @param day If Frequency is monthly, the day of the month (1, 5, 10, 15, 20, 25) to trigger the order on.
  @param instalments Number of instalments to trigger. If set to -1, instalments are triggered at fixed intervals until the SIP is cancelled.
  @param sipId is the id of the sip.
  @return returns true, if modify sip is successful else exception is thrown.
  @throws KiteException is thrown for all Kite trade related errors.
  @throws IOException is thrown when there is connection related error.