Merging between two projects (Master)

Currently we are using SVN and we are planning to migrate to GIT.

The below is the current structure in SVN we are able to merge changes from core to branches and branches to core.

trunk (core project)

  • client 1
  • client 2
  • client 3

We are planning to migrate to GIT core is one master and each client project is as a separate master.

Can we merge the file between two masters?