Hi,

You can use URL redirection function.

1.Install IIS on the report server. create a website with 80 port.

2.In this site, create a HTML web page with the following code:

<script>window.location = 'http://www.mywebsite.com/reports</script>

3.Save the file to be Default.Html. This file to used to redirect the user to the report manager on the file loading.

For more information, please refer to this thread:

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/86932bb5-a721-47ff-8ed0-1e144c87be4d/ssrs-2008-url-redirecting?forum=sqlreportingservices