Hi @rachitha88 ,
Welcome to the community!
I found a thread about connecting a 3rd party Netgear modem/router that you may find helpful.
Please visit the link below.
Credits to @2fly
You may also follow this connection setup.
Username: <Your TPG username>
Password: <Your TPG Account Password>
Protocol / Encapsulation / Connection Type: PPPoE(sometimes, you'll have PPPoE LLC)
VLAN ID: 2
We'd like to set your expectation that the VOIP service will not work should you proceed in using your modem as it is only provisioned on the TPG supplied equipment.
Let us know how it will go.
This router only has a RJ11 port to connect to telephone wall socket so it is only for FTTB/FTTN. You also need the updated firmware to do VDSL.
(The updated firmware may - or may not - have created an ethernet WAN port out of a LAN port so the router could be used on other NBN types.)
Settings are PPPoE, username with @TPG.com.au on the end, and password. Also need VLAN ID=2 but you have to look through the menus.