csr: 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/bin/csr - from package: rheolef

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