Save to older version of EPS or AI
CS6 does not appear to allow the user to save to older versions of EPS or AI. Many vendors and designers are still using older versions, and the inability to save to older versions is creating a lot of problems.
It should be possible to do so through File > Save As… then select the Format as .ai or .eps, then click Save. In the next dialog select the desired version from CC to Ai3.