If you have a Creative Cloud subscription, here is how to find it:
1. Go to creative.adobe.com. Sign in with your Adobe ID.
2. Scroll down to InDesign. DON'T click DOWNLOAD. Click the word "InDesign" to go to the InDesign product page.
3. Under the head "In This Version," there is a menu. Choose InDesign CS6.
4. Click Download InDesign CS6.