dtrealms: 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/dtrealms - from package: dnssec-tools

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

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