What version of Photoshop do you have?
While ACR 8.4 supports the Sony Alpha 6000, you need CS6 or CC to be able to use ACR 8.4
If you have CS5 or older you can download the latest version of the DNG Converter to convert your files to DNGs that can be opened in older versions of ACR/Photoshop.
The DNG Converter converts folders of files, not individual files. Select the folder, not a single file.