nmblookup: 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/nmblookup - from package: samba4-client
/usr/bin/nmblookup - from package: samba-client

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

On Debian possible default full paths are:

/usr/bin/nmblookup - from package: samba-common-bin

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

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