Apache Tomcat is an open-source software implementation and not part of the
Trados GroupShare Installer.
On the 64-bit systems, you need the 64-bit version of Apache Tomcat and you can also choose to download a newer version from
http://tomcat.apache.org/.
As per
Trados GroupShare 2020 SR1 Installation Guide you can use Apache Tomcat 9.
Follow the above
Trados GroupShare 2020 SR1 installation guide - and save any customized changes you might have had for your
MultiTerm Online installation (e.g: mtonline.properties) or any profiles saved under
C:\Program Files\Apache Software Foundation\Tomcat X.X\webapps\multiterm\WEB-INF\profiles.