jsvnadmin: 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 Debian possible default full paths are:

/usr/bin/jsvnadmin - from package: svnkit

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