Where do I find the app Indesign CS6 (I had previously CC2014 but now I need to have a monthly or yealy plan for CS6)?
You'll have to purchase a Creative cloud subscription for InDesign CC 2015, along with it you'll get InDesign CS 6 with in that subscription, there is no separate way to get InDesign CS 6 as a subscription.
Please see Install Previous Version Apps section in the below link to get more info :
You can access the link (Download Creative Suite 6 applications) if you have a Perpetual License of InDesign CS6 purchased and activate InDesign CS6 with the license serial key.
If you have a Creative Cloud Membership, open the Creative Cloud App
Click on the ""App"" tab at the top
Click on ""Filters and versions"" or ""All Apps"" in blue at the right and click on ""Previous Version"" in the drop down
You will have ""install"" tab besides the product
Click on ""Install"" and in the drop down, you will have option to download CS6 Version of that product.