texsis: 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/texsis - from package: texlive

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

On Debian possible default full paths are:

/usr/bin/texsis - from package: texlive-formats-extra

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

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