Synchronization

I plan to sync users from a master site to a sub site and I intend to keep roles different from one another. Is there a way to define which role will be used in the sub site?

Ex.: The users in the master site are associated to the role 'contributor' and in the sub site they should be associated to the role 'subscriber'.

to another and but in the master site the users are associated to the role 'contributor'. I need to set the users in the sub site with role 'subscriber'.