I have a MacBook Pro 15", Mid 2015 macOS Sierra. Can I install a newer operating syatem in my computer?

Heefner wrote:

I have a MacBook Pro 15", Mid 2015 macOS Sierra. Can I install a newer operating syatem in my computer?

You will need to get to at least High Sierra first before you can go further.

Your 2015 MBP is quite capable of running the latest macOS Big Sur—if you meet all the tech specs:

Big Sur macOS 11.6

https://support.apple.com/macos

The older macOS installer backups on this server:

https://support.apple.com/en-gb/HT211683

verify you are using the Safari browser to download/initiate the macOS links.

Yes. Your MacBook Pro is compatible with the latest release of macOS, Big Sur. If you would like to upgrade, you can do so by following the steps here.