I am trying to install Big Sur OS and it gets "stuck" every time with 12 minutes remaining. Any ideas?

What version of macOS are you running? You need 35.5GBs of free space for Sierra and later, 44.5GBs pre-Sierra.

If you have the free space available, try installing while in Safe Mode.

How to use safe mode on your Mac - Apple Support

That's why I suggested Safe Mode. Just in case you made the mistake of installing antivirus/security software.

Later tonight I'll be posting instructions for a new way that I developed to install Big Sur, which should solve your issues.