rosco: 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/rosco - from package: python-rosinstall

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