why i cant upgrade my macbook pro i have version10.11.6

How to:

• Identify your MacBook Pro model - Apple Support

https://support.apple.com/en-us/HT201300

"MacBook Pro models from 2012 and newer can run the

latest version of macOS. ~ For models from before 2012,

the latest compatible operating system is noted."

Models shown in this article can run 10.11.6 & Newer. Hardware

goes back to "Early 2008." ~ The next recent macOS 10.13.6 runs

in "Mid 2010." These are all different configurations, CPU/GPU,

display size, technologies, etc. The correct macOS for upgrade

is linked by its build year model, to Mac system software; and

installers and software gets downloaded from Apple servers.

Learn how to identify by several clues, sales order number, and

others; helps determine which configuration runs what macOS.

Take care & good luck!🌞⛵️

There's some information here:

• Identify your MacBook Pro - Apple Support

https://support.apple.com/en-us/HT201300

• Mac OS Compatibility Guide by Mac Model | macsales/guides

https://eshop.macsales.com/guides/Mac_OS_X_Compatibility

"Easily check which versions of mac OS, iOS, iPadOS, or watchOS

are compatible with your Mac model or iDevice.

Guide includes OS X 10.8.x to macOS 11.0.x".

If your Mac needs older software with 32-bit drivers, etc

you may consider (if your Mac isn't too old) an upgrade

to Mojave macOS 10.14.6. [Some 'third-party software' has

no upgrade to 64-bit drivers for Catalina or later macOS.]

• How to upgrade to macOS Mojave (10.14.6) - Apple Support

https://support.apple.com/en-us/HT210190

Depending on build year. sales order, model number, an idea of

exact upgrade(s) past El Capitan 10.11.6 can be recommended.

Some require upgrades to Mac's RAM and Storage capacity.

For hardware upgrades, where possible, without commitment:

see examples of what parts are available @ OWC to ready Mac..

Take care & good luck!🌻🐝

MacBook Pro models from 2011 or older are not supposed beyond 10.11 El Capitan, because their graphics chips and processors are not capable enough to show more recent McOS without substantial delays in displaying ordinary information and doing encryption.

what model Mac by year, early mid late, screen size and processor speed?

Hi,

It depends on which model of MacBook Pro are you using.