LR doesn’t use the ACR plug-in, only Photoshop. What are you trying to do, exactly?
You can download the DNG Converter 8.6 RC and convert your NEFs to DNGs, one folder at a time, then those would import in LR, but otherwise, installing a PS plug-in isn’t going to affect LR.
The DNG Converter is part of the CS6 ACR 8.6 RC set of downloadable files at Adobe Labs, not part of the CC set.