According to this Adobe help link, the 5D Mark III had support since Camera Raw version 7.1 and the 70D had support since version 8.2, which CS6 should support fully. (CS6 supports up to the latest Camera Raw, which is version 8.7 as of this post.)
Is everything updated? (Help > Updates in Photoshop.)
Update Photoshop once.
Open Photoshop. Click on Help in Photoshop menu and choose Updates.
Follow onscreen instructions.