i upgrade to lightroom 6, but still can importing cr2 files.
i did the update for raw files 9.3, still can importing them
Please state what camera took these CR2 photos.
Updating Camera RAW has no impact on Lightroom.
See if the info available at the above link provides the help you need. You should update to Lightroom CC 2015.8 / LR 6.8, its a free update.
You do not need to uninstall the version of Lightroom 6 you have installed just run the update patch after downloading.