/usr/include/sipxtapi/tao/ is in libsipxtapi-dev 3.3.0~test17-2.1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sipxtapi/tao/TaoAdaptor.h
/usr/include/sipxtapi/tao/TaoAddressAdaptor.h
/usr/include/sipxtapi/tao/TaoCallAdaptor.h
/usr/include/sipxtapi/tao/TaoClientTask.h
/usr/include/sipxtapi/tao/TaoConnectionAdaptor.h
/usr/include/sipxtapi/tao/TaoDefs.h
/usr/include/sipxtapi/tao/TaoEvent.h
/usr/include/sipxtapi/tao/TaoEventDispatcher.h
/usr/include/sipxtapi/tao/TaoEventListener.h
/usr/include/sipxtapi/tao/TaoListenerClient.h
/usr/include/sipxtapi/tao/TaoListenerEventMessage.h
/usr/include/sipxtapi/tao/TaoListenerManager.h
/usr/include/sipxtapi/tao/TaoListeningTask.h
/usr/include/sipxtapi/tao/TaoMessage.h
/usr/include/sipxtapi/tao/TaoObject.h
/usr/include/sipxtapi/tao/TaoObjectMap.h
/usr/include/sipxtapi/tao/TaoPhoneComponentAdaptor.h
/usr/include/sipxtapi/tao/TaoProviderAdaptor.h
/usr/include/sipxtapi/tao/TaoProviderListener.h
/usr/include/sipxtapi/tao/TaoReference.h
/usr/include/sipxtapi/tao/TaoServerTask.h
/usr/include/sipxtapi/tao/TaoString.h
/usr/include/sipxtapi/tao/TaoTerminalAdaptor.h
/usr/include/sipxtapi/tao/TaoTerminalConnectionAdaptor.h
/usr/include/sipxtapi/tao/TaoTerminalConnectionListener.h
/usr/include/sipxtapi/tao/TaoTransportAgent.h
/usr/include/sipxtapi/tao/TaoTransportTask.h