I'm a bit unclear as to your ask, but if you are asking to download the most recent GRC 6.1 installation files, there is a process, including a new License Key required before access to the install packages are available for download to you. Your 5.5 License Key will not allow download access to GRC 6.1 install packages. There is no current GRC 6. 1 License key info that I could locate today, Sunday.
In the interim, please check out the GRC 6.1 Upgrade process document on the Overview page of the private Archer Customer/ Partner Community: Archer Customer/Partner Community
If it is to download the 5.5 Install packages, the T-System License Keys appear to have all expired. If you believe this is a mistake, you should contact your Account Rep,Ulrike Waizennegger immediately.
I have also reached out to confirm that the expired License key information is indeed the most accurate and will amend this post as soon as I received confirmation.