tg-admin: 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/tg-admin - from package: TurboGears

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

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