@Sarang 

Hello,

For this issue, we would like to collect some information first so that we can locate the issue quickly and provide you some suggestions.

Does the internet light which looks like a globe/ planet on the front panel of this router lit up or not? 

1. If the light is off, please check if the WAN port(blue port) of the router is connected to the modem with Ethernet correctly, you need to check all of the Ethernet cable, modem, etc.

2. If the internet light is on, please unplug the Ethernet cable from the blue Ethernet port of the TP-Link router, then plug the same cable directly to your computer(Which means from your modem go straight to your computer, bypass the TP-Link router) and disable the wifi on your computer then check if you have the internet on the computer,  If there's no internet, please contact your ISP to check the internet or modem.

If the computer has internet access,  please power off the modem for about 3 minutes then power it on again(Keep router on). But if the router still doesn't have internet after rebooting the modem, please log in to TP-LINK web interface page following the link:
https://www.tp-link.com/en/support/faq/2837/

Then go to Advanced > Status and take a whole status page to us.

Please also tell me the LED light status on the router, thank you!

The hardware version and firmware as well.

Hardware:  you can find at the bottom label of the product, which begins with Ver.xx

Firmware: https://www.tp-link.com/en/support/faq/1991/

BTW, which country are you located in? If you are from the US, you can try Dynamic IP.

Note, if you choose PPPoE, please make sure your account username is an e-mail form.

May it help and have a nice day!