Upgrade (and evalation) packages for Tectia Client and Server are available at http://www.ssh.com/index.php/evaluation-downloads.html.
Tectia Manager requires license files for imported managed software.
The maintenance release (for example 6.3.3) packages do not contain license files. However, you can use a maintenance release package if you already have a license for the same (minor) release (for example 6.3).
When importing an update package, Tectia Manager will look for the product license file for the same version (6.3). For example, when importing a Tectia Client 6.3.3 update package, there should be a previous license for Tectia Client 6.3 imported in Tectia Manager.