mongorestore: 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/mongorestore - from package: mongodb

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

On Debian possible default full paths are:

/usr/bin/mongorestore - from package: mongodb-clients

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