runtools: 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/runtools - from package: texlive-context

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

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