indexcon: 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/indexcon - from package: setools-console

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

On Debian possible default full paths are:

/usr/bin/indexcon - from package: setools

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

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