unable to open some websites on safari

Hi,

Post to the latest update i am unable to use 50% websites through any of my web browser, however if i use it with different device, i am able to open them. I understand it is due to some DNS server setting however unable to fix the same. Can any one help me to get this sorted i am actually running behind of my project and the last resort which i can understand it restoring my mac to factory reset.

Kind Regards,

D