aclocal-1.6: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/aclocal-1.6 - from package: automake16

You may install the required package with command yum install {package}
Error in other languages:
aclocal-1.6: bevel nie gevind nie
aclocal-1.6: comandă negăsită
aclocal-1.6: comando não encontrado
aclocal-1.6: commande introuvable
aclocal-1.6: command not found
aclocal-1.6: käsku ei ole
aclocal-1.6: không tìm thấy lệnh
aclocal-1.6: komanda nerasta
aclocal-1.6: Kommando nicht gefunden.
aclocal-1.6: kommandot finns inte
aclocal-1.6: komut yok
aclocal-1.6: nie znaleziono polecenia
aclocal-1.6: níor aimsíodh an t-ordú
aclocal-1.6: no se encontró la orden
aclocal-1.6: no s'ha trobat l'ordre
aclocal-1.6: opdracht niet gevonden
aclocal-1.6: parancs nem található
aclocal-1.6: perintah tidak ditemukan
aclocal-1.6: príkaz nenájdený
aclocal-1.6: příkaz nenalezen
aclocal-1.6: команда не найдена
aclocal-1.6: командата не е открита
aclocal-1.6: 命令找不到
aclocal-1.6: コマンドが見つかりません