It depends on
- what installer package you are trying to download - some are over 6 GB, which can take up to 30 minutes to complete
- your Internet connection; I am 10,000 km away from the Adobe download servers, but every download completes within a few minutes
Try downloading the offline installers from http://prodesigntools.com/adobe-cs6-direct-download-links.html
Make sure you follow the Very Important Instructions on that page.