condor_release: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/condor_release - from package: condor

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/condor_release - from package: htcondor

You may install the required package with command apt-get install {package}

Error in other languages:
condor_release: bevel nie gevind nie
condor_release: comandă negăsită
condor_release: comando não encontrado
condor_release: commande introuvable
condor_release: command not found
condor_release: käsku ei ole
condor_release: không tìm thấy lệnh
condor_release: komanda nerasta
condor_release: Kommando nicht gefunden.
condor_release: kommandot finns inte
condor_release: komut yok
condor_release: nie znaleziono polecenia
condor_release: níor aimsíodh an t-ordú
condor_release: no se encontró la orden
condor_release: no s'ha trobat l'ordre
condor_release: opdracht niet gevonden
condor_release: parancs nem található
condor_release: perintah tidak ditemukan
condor_release: príkaz nenájdený
condor_release: příkaz nenalezen
condor_release: команда не найдена
condor_release: командата не е открита
condor_release: 命令找不到
condor_release: コマンドが見つかりません