tcprules: 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/tcprules - from package: ndjbdns

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

On Debian possible default full paths are:

/usr/bin/tcprules - from package: ucspi-tcp-ipv6
/usr/bin/tcprules - from package: ucspi-tcp

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

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