There is no option to link to external sources of jar files within an update site. Doing this would be error prone, as your code might depend on a specific version of a jar file and might break if the user gets a newer, incompatible version.
The solution for this is a proper dependency management:
@jagadish if you use Maven to build your plugin, the dependencies of your plugin will be known to the updater, and it will prompt you to also upload the required dependency jar files when you upload your plugin to your update site. Have a look at the
example-legacy-plugin) projects to see how dependencies are defined in a
If you post a link to your source code (preferably on github), someone here on the forum will be able to help you mavenizing your project.