There are ClearCase extension versions available for JDeveloper and, as any given release of SQL Developer is based on some JDeveloper release, you may be able to find an appropriate version of the extension for your use case. Look for ClearCase in the JDev update center:
Of course ClearCase is not listed in the SQL Developer release notes as a supported Version Control System:
If you wish to give it a go, however, here is what I did to install a ClearCase extension for my 4.0.1 SQL Developer...
1. Check SQL Developer's Help > About > Extensions for the version of oracle.jdeveloper.vcs (220.127.116.11.41.140207.1351)
2. Downloaded vcs-clearcase_bundle.zip (18.104.22.168.40.66.68 is the closest available JDev version)
3.Within the zip file, edit/replace the maxVersion value in the META-INF\bundle.xml file (from 22.214.171.124.40.66.68 to 126.96.36.199.42.99.99)
4. Install from the zip: Tools > Features... > Check for Updates (upper right corner) > Install From Local File (radio button) ...
5. Now ClearCase will be available from the main toolbar: Team > ClearCase
I do not have ClearCase installed on my machine so this is as far as I could go. Hopefully you will make further progress.
SQL Developer Team