Extended Support for 11.2.0.4 ended on December 31, 2020. Security patches are generally not available unless you have purchased an Extended Support or Market Driven Support contract.
After installing the core 11.2.0.4 software, it is highly recommended to apply the latest Patch Set Update (PSU) or Bundle Patch to secure the database. oracle database 11g release 2 11.2 0.4 download
The primary repository for this version is My Oracle Support. Downloading requires an active account associated with a paid Support Identifier (CSI). Navigate to the My Oracle Support portal. Extended Support for 11