Hi @BalajiAS,

If you can access other websites/Apps without any issues but having trouble accessing specific websites/Apps, please refer to the following steps for troubleshooting.
    1. Disconnect the Router from your Modem and connect your PC directly into the Modem, verify if the PC could access this specific websites/Apps, it might be an ISP issue if your PC is not able to access this specific website/Apps.
    2. If you have the Real-Time protection of HomeShield Pro enabled, please check the Real-Time protection history, if the specific website is blocked by mistake, please reach out to TP-Link support for resolution.
    3. Check the Parental Control settings, including content filtering and website blocking.
    4. Try a Mac Clone of your PC if your PC is able to access the site when connected into the modem directly. Login to the router's web management interface and go to Advanced > Network > Internet > "MAC Clone", select your PC's mac address for cloning.