For Macs running macOS Ventura or Sonoma, CS6 is dead. You have no choice but to switch to Premiere Pro CC (or DaVinci Resolve/Final Cut Pro). The monthly subscription is the price of using a modern OS.
Adobe no longer supports CS6 (released in 2012). It is not available for legal free download from Adobe. This article explains your actual options, system requirements, and how to access legitimate copies. adobe premiere pro cs6 mac os x download
Even with an installer, the software will not function without a valid, original serial number and a one-time internet activation. For Macs running macOS Ventura or Sonoma, CS6 is dead