Raw Conversion

You can also use File>Process Multiple Files in the photoshop elements editor.

You can import those NEF files in Elements Organizer.

Select those files and go to File > Export

In Export dialog, choose the format you want to convert the files to and the location where you want to save the exported files.

Upon doing so, click on Export. Your NEF files would be exported to the chosen format.

For more details, please see Export photos to a folder in Elements Organizer

Thanks,
Anwesha