chcon: 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/chcon - from package: coreutils

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

On Debian possible default full paths are:

/usr/bin/chcon - from package: coreutils

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

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