I have checked here and noted that you have NBN FTTC service so you still need NBN NCD. you can try your router instread of Tp link Archer 1600v but i am not sure it can work or not and make sure connect via WAN port ( red colored ).
See below link for manual of router.
you need to use PPoE and you need to use VLAN 2 and you also need your TPG Username and password but i am not sure those change are available or not in that router.
Otherwise you can add your Dlink router to existing Tp link router, you just need to use one of Ethernet port of Tp link router to WAN port and you can select dynamic ip address. you can also turn off wireless for tp link router if you want dlink router as a main router for wireless.