rbt: 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/rbt - from package: RBTools

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

On Debian possible default full paths are:

/usr/bin/rbt - from package: python-rbtools

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

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