64tass: 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/64tass - from package: 64tass

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

Error in other languages:
64tass: bevel nie gevind nie
64tass: comandă negăsită
64tass: comando não encontrado
64tass: commande introuvable
64tass: command not found
64tass: käsku ei ole
64tass: không tìm thấy lệnh
64tass: komanda nerasta
64tass: Kommando nicht gefunden.
64tass: kommandot finns inte
64tass: komut yok
64tass: nie znaleziono polecenia
64tass: níor aimsíodh an t-ordú
64tass: no se encontró la orden
64tass: no s'ha trobat l'ordre
64tass: opdracht niet gevonden
64tass: parancs nem található
64tass: perintah tidak ditemukan
64tass: príkaz nenájdený
64tass: příkaz nenalezen
64tass: команда не найдена
64tass: командата не е открита
64tass: 命令找不到
64tass: コマンドが見つかりません