What version of the action pack are you using?
I just installed version 10.5.1412.1 in version 6.5 of RA and tested the action. I configured my action with the following in each of its fields:
Artifact Path: /path/to/my/file/on/agent/machine
Nexus Url: http://myservername:8080/nexus
Repository Id: TestRepo (which already exists)
Group Id: abc (which did not exist)
Artifact Id: def (which did not exist)
Version Id: 12.1 (which did not exist)
Packaging: sh
Artifact Classifier: myclass
user: admin
password: mypassword
After testing the action I see that it created an artifact with the following details:
<dependency>
<groupId>abc</groupId>
<artifactId>def</artifactId>
<version>12.1</version>
<classifier>myclass</classifier>
<type>sh</type>
</dependency>
And its end url:
http://myserveername:8080/nexus/service/local/repositories/TestRepo/content/abc/def/12.1/def-12.1-myclass.sh
Kind regards,
Gregg