My team just upgraded to CC. Two still have running their macs on 10.6.8 and I have 10.7.5.
I just realized a compatibility issues with our Indesign versions. I was upgraded to CC2014 and they have just CC. They are unable to open my files. Can this be resolved without updating system software? I am assuming that is the reason I have a different version of Indesign?
CC2014 requires 10.7 at a minimum. You can install that but its time for
everyone to move to a new O/S.
In general, while you don't need the latest operating system, you shouldn't fall too far behind. The current operating system (Yosemite) is 10.10. Being four versions behind is looking for trouble if you're expecting to run modern software.