There aren't any Debian versions on which SecureCRT is supported, because Debian isn't a targeted platform for SecureCRT development.
See System Requirements (supported OSes) for clients on our website here.
If you would like support for Debian (or any other currently unsupported OS), let us know using
this form from the support page of our website and if it becomes available, we will post here.
In the meantime, if you're adventurous enough and you don't have any problems running unsupported software on your system and living with any subsequent problems that you might encounter, you might be able to get your SecureCRT working with these steps.