Microsoft has release version 11 of Internet Explorer, but decide when you should update.
As with any product, you should keep yourself protected by applying patches and updates, and even upgrade to the latest version when possible. When and how you should do this depends on a variety of factors that will no doubt be unique to you and your organisation. Your Information Security management system should set out the criteria for assessing new versions and how to test products before rolling out an update.
Internet Explorer version 11 is no exception.
Before you download, see https://technet.microsoft.com/en-us/ie/mt163707.aspx for more details.