I'd guess that this is most likely a firewall issue. Can you speak to the people in your organization who manage the firewalls and make sure that they are set up to allow the traffic to flow through?
It may also be a problem with your security groups on AWS, so check those as well.
Hi ..i think tableau server is made secured on purpose and isnt exposed to outside network directly. need to configure some proxy server. dont know whats the exact process