InDesign CS6

Thanks everyone!!
Great Advice - Very helpful forum

You said that you are already subscribing to two Creative Cloud apps which means, if I am reading it right, you are now paying about $42 per month for just the two apps. For just an additional $10 per month not only would you get access to all creative cloud versions of InDesign and Illustrator but all of the other Adobe apps as well as full access to updates as they come out. If, as Bob suggests, you were to find some other apps to use in place of InDesign and Illustrator I would think that you would be spending at least the $10 monthly for apps which are not the industry standard. The $10 extra a month just seems to make sense to me.

As Steve says, but there are alternative applications out there that you might want to explore.

The capture you are showing means the document was saved with a newer InDesign version, so if you can get the provider to save as an .idml you will be able to work on it in CS6, which can run on the latest 10.13.4.

The new High Sierra is throwing up the 64-bit message for all non 64-bit apps on their first launch, but none of those apps are actually affected. So, until Apple releases a system that won't run 32-bit, CS6 will run. When that actually happens you might decide to continue with High Sierra unless there are OS features that are more valuable than the upgrade of CS6 an other 32-bit apps.

Frankly, I cannot afford or justify Indesign or Illustrator CC for the number of times I would use it in a yearly period :-( Basically, Is there a work-a-round so I can open the Indesign or Illustrator files with my version of CS6?

When the OS change comes you could also install an earlier OS on an external SSD drive and start from that OS on the few occasions where you need ID. Look at an app like Carbon Copy Cloner, which will make bootable clones of any startup volume. I have an older app that is no longer being developed, which I still need occasionally, so I run it off of a Mavericks partition.