1)Who should do the communication on a project dependent on the organization set-up?

Communication in any project is an essential tool for a PM, also regardless of your role on the project, you must learn how to communicate effectively (with the project team members or with a client) to be successful. Communication is the key for success for any project.

2)What means or platform should be done to communicate in a professional situation?
Communication is not only about speaking to and hearing from people, it’s about understanding the complete message regarding any topic. For a PM, effective communication comes from spending time with the project team, being fully engaged and prepared to listen to your project members.