nicstat: 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/nicstat - from package: nicstat

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