nslogin: 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/lib/rancid/bin/nslogin - from package: rancid

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