Hey Khan,
These features are not provided by OOTB AEM.
You need to extend libs.granite.sightly.templates.ClientLibUseObject and add your methods to the Object you will create.
Example by Nate Yolles, is actually pretty good(as always his examples are), it needs to be adapted to 6.4 as you said,
htmlLibraryManager in 6.4 knows how to write js include and css include, you can use that, the only difference would be that before the out.write you would need to replace the output with your additional attributes.
Regards,
Peter