Amazon RDS for Oracle now supports the April 2019 Patch Set Updates (PSU) for Oracle Database 11.2 and 12.1, and April 2019 Release Update (RU) for Oracle Database 12.2.

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/05/amazon-rds-for-oracle-now-supports-april-oracle-patch-set-updates-psu-and-release-updates-ru/