i want to implement a mvc module as jira webwork1 module type, but i dont know how to render a vm template file which in another plugin. anyone can help me. thanks.
You can't really do that. A .vm file requires a "context" which is provided by the code behind it. You can't just take a .vm and render it from elsewhere because the context for it won't be there in your code. You can, of course, create your own context for a .vm file provided elsewhere, but you might as well just copy the .vm into your own plugin as you're already doing all the rest of the work.
The jar plugin is a simple zip archive. Unzip the plugin you want to get vm from and copy vm into your plugin. Then render that according to your needs. Please note that you should provide needed variables to that vm file to render it. Also please note that there might be some license issues that will not allow to do that legally.