tc: 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:

/sbin/tc - from package: iproute

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

On Debian possible default full paths are:

/sbin/tc - from package: iproute2

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

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