nad2bin: 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/nad2bin - from package: proj

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

On Debian possible default full paths are:

/usr/bin/nad2bin - from package: proj-bin

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

Error in other languages:
nad2bin: bevel nie gevind nie
nad2bin: comandă negăsită
nad2bin: comando não encontrado
nad2bin: commande introuvable
nad2bin: command not found
nad2bin: käsku ei ole
nad2bin: không tìm thấy lệnh
nad2bin: komanda nerasta
nad2bin: Kommando nicht gefunden.
nad2bin: kommandot finns inte
nad2bin: komut yok
nad2bin: nie znaleziono polecenia
nad2bin: níor aimsíodh an t-ordú
nad2bin: no se encontró la orden
nad2bin: no s'ha trobat l'ordre
nad2bin: opdracht niet gevonden
nad2bin: parancs nem található
nad2bin: perintah tidak ditemukan
nad2bin: príkaz nenájdený
nad2bin: příkaz nenalezen
nad2bin: команда не найдена
nad2bin: командата не е открита
nad2bin: 命令找不到
nad2bin: コマンドが見つかりません