The installer works in 11.0 with no problems when server requirements are met. Maybe you are missing some php-mysql package from the repos?
Do applications like phpmyadmin work on your server?
Install phpmyadmin first, for instance, and it will pull all the other required packages for the communication between php and mysql apps.
Once you succeed with it (log in phpmyadmin, create a database, etc), you can try again with your Tiki.
Cheers, and welcome to the Tiki Community