rpsblast: 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/rpsblast - from package: blast2
/usr/share/ncbi-blast+/bin/rpsblast - from package: ncbi-blast+-legacy

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

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