Hi,
After trying a lots of configurations, I find the solution !
In my syncrepl configuration I was filtering on (cnrsdelagation=DR13*)
Of course openldap was not able to get entries for "ou=people,dc=compagnise,dc=com" because it is an organizationalUnit object!
I just modify the filter in syncrepl config : (|(cnrsdelagation=DR13*) (objectclass=organizationalUnit)) and now it works fine !
Thanks for everybody !