tomoyo-setlevel: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/sbin/tomoyo-setlevel - from package: tomoyo-tools

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