Hi @chetan8626,
As @KarthikByggari suggested the issues seems to be due to the firewall blocking the connection between your machine and the activation server from UiPath.
Error while activating UiPath Community Edition - #4 by Sri_harsha_Bhasuru.
If you have tried it with not success then I would try to use offline activation
Studio - Activate Studio
Let’s us know your progress 
Best Regards,
Susana