tsql: 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/tsql - from package: freetds

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

On Debian possible default full paths are:

/usr/bin/tsql - from package: freetds-bin

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

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