I will assume it as a general case (an otside country/researcher is asking to join a project he/she read about in the RS website.
I suggest that: 1. A dialoge can be started between the 2 parties after reading the CV of the new commer, 2. A deal or a MOU may be signed documenting how the new commer will help positevly in the project he asked to join it, 3. If the joining request is to study a thesis, one of the project's member shall share supervising the person, (4) gradually the work will be in a perfect progress, 5. Results of the work will be have greare value for both sides.