Perhaps you could describe the problem a little more? I assume you mean Import when you say Upload. After you try to import the RAW NEF file, what happens? If there is an error message, please quote the unedited complete verbatim word-for-word error message.
Also, please state your version of Lightroom and what camera is taking these photos.
No, there is no plug-in. What version of Lightroom? What camera model? Here is a list of all the cameras supported by Lightroom, and the minimum version of Lightroom and Camera Raw required for each camera model: