tpm_unsealdata: 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
/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/tpm_unsealdata - from package: tpm-tools

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

On Debian possible default full paths are:

/usr/bin/tpm_unsealdata - from package: tpm-tools

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