nfc-relay-picc: 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 Debian possible default full paths are:

/usr/bin/nfc-relay-picc - from package: libnfc-bin

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

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