If the configuration is correct and you are using maven-release-plugin which means
mvn release:prepare
than a SVN tag is created automatically by Maven. So there is no need to check. Apart from that it could happen that you need to change the tag-Base in the Maven-release-plugin if you have a different SVN layout which is not like:
Repo
+-- Project
+--- trunk
+--- tags
+--- branches
which means you need to configure the maven-release-plugin:
<project>
...
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-release-plugin</artifactId>
<version>2.4.1</version>
<configuration>
<tagBase>https://svn.mycompany.com/repos/myapplication/releases</tagBase>
</configuration>
</plugin>
</plugins>
...
</build>
...
</project>