Nutshell: whatever versions are used by the Struts 2.2.3 Tiles and Jasper plugins.
That it's being asked means you're not using Maven, instead managing transitive dependencies by hand--this is almost always a Really Bad Idea. Can't urge you strongly enough to not do this.
Long answer: When you have questions like this, use the Maven config files and/or Maven itself to find the answers, because that's how Struts 2 is being built.
You can use sites like http://mvnrepository.com when the info is explicit in the pom.
Struts 2 JasperReports Plugin Dependencies: JasperReports 3.1.2
Struts 2 Tiles Plugin Dependencies: Tiles 2.0.6, but not as easy to figure out since the Tiles version isn't explicit in the POM. Running mvn dependency:tree
shows that it's 2.0.6:
[INFO] org.apache.struts:struts2-tiles-plugin:jar:2.2.3
[INFO] +- org.apache.tiles:tiles-core:jar:2.0.6:compile
[INFO] | +- org.apache.tiles:tiles-api:jar:2.0.6:compile
[INFO] | +- commons-digester:commons-digester:jar:2.0:compile (version managed from 1.8)
[INFO] | | \- commons-beanutils:commons-beanutils:jar:1.8.0:compile
[INFO] | \- commons-logging:commons-logging-api:jar:1.1:compile
[INFO] +- org.apache.tiles:tiles-jsp:jar:2.0.6:runtime
... etc ...