nxagent: 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/nxagent - from package: nxagent
/usr/lib64/nx/bin/nxagent - from package: nxagent

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

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