You bought a CD, madness.
If you want to upgrade your Mac from Yosemite to another newer OS you have three alternatives..
El Capitan, Sierra and High Sierra are all available for download and are free.
It sounds like you have been trying to install updates to El Capitan downloaded from the Apple Support Downloads pages. If so you need to have already installed El Capitan, that is why you are getting the message about 10.11.
for example if you downloaded the 10.11.6 Combo update this will update any previous version of El Capitan from 10.11.0 to 10.11.5 to the last version 10.11.6. Please remember full versions of OS's are only available via the Mac App Store.
Depending on the age of your Mac you may not be able to upgrade to Sierra or High Sierra, if so you should be able to upgrade to El Capitan.
Dec 08, 2015 The OS X El Capitan v10.11.2 update improves the stability, compatibility, and security of your Mac, and is recommended for all users. This update: Improves the reliability of Handoff and AirDrop. Fixes an issue that may cause Bluetooth devices to disconnect. Fixes an issue that prevented Mail from deleting messages in an offline Exchange account. Download Mac OS X El Capitan 10.11.6 Bootable DMG Image Free, macOS El Capitan 10.11, Apple OS X El Captain latest version, Mac OS X with best performance and stability, Gesture improvements, OSx.
Have a look at the links below to determine what OS you would like to download. Bear in mind though that if your Mac qualifies for High Sierra then you will be denied the download of El Capitan.
The versions that will be downloaded in each case will be the latest versions of each OS, so for El Capitan it will be 10.11.6, Sierra will be 10.12.6 and High Sierra will be 10.13.3.
If you tried Erics link to El Capitan and you couldn't download it, then the App Store is recognising that you Mac qualifies for High Sierra, so you can upgrade to that or if you want you could also upgrade to Sierra from the link above.
Feb 28, 2018 12:24 AM
To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.
Learn how to upgrade to macOS Big Sur, the latest version of macOS.
Check compatibility
The version of macOS that came with your Mac is the earliest version it can use. For example, if your Mac came with macOS Big Sur, it will not accept installation of macOS Catalina or earlier.
If a macOS can't be used on your Mac, the App Store or installer will let you know. For example, it might say that it's not compatible with this device or is too old to be opened on this version of macOS. To confirm compatibility before downloading, check the minimum hardware requirements:
- macOS Catalina 10.15 hardware requirements
- macOS Mojave 10.14 hardware requirements
- macOS High Sierra 10.13 hardware requirements
- macOS Sierra 10.12 hardware requirements
- OS X El Capitan 10.11 hardware requirements
- OS X Yosemite 10.10 hardware requirements
Download macOS using Safari on your Mac
Os El Capitan 10.11 6 Download Full
Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.
- macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
- macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
- macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
Can I Upgrade From El Capitan 10.11.6
Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.
Os X El Capitan Iso Direct Download
- macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
- OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
- OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard