qtcsh: 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/qtcsh - from package: gridengine
/usr/share/gridengine/bin/lx26-amd64/qtcsh - from package: gridengine
/usr/share/gridengine/bin/lx26-x86/qtcsh - from package: gridengine

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

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