Reverting back to MacOS Catalina

Recently I had upgraded to Big Sur,but dur to lagging issues and application support I decided to revert back to Catalina using Time Machine backup.But when I reinstalled the OS it just doesn’t load in the startup and says unrecoverable error:prelogin .

I also tried reinstalling the Catalina OS from recovery mode ,but it says resources not available to install this version of MacOS .

What should i do now?