Premiere Pro CS6 doesn’t support 4K, as it came along before the wide use of 4K. Premiere Pro in the current Creative Cloud subscription plan will support 4K and a subscription to just PPRo is around $20/month.
If you’re creating a custom project in CS6, save it under a generic name such as “4K Template” or with a configured sequence but without any assets, then open it and save it under a name that relates to the project you’re starting. I keep an “untitled” project on my desktop that I often use for quick projects and do this frequently.
