If I am in target group 2, do I need to be registered at a home University?

No. It is not a requirement for Target group 2 candidates to be registered with a Home University (means a University in their country which is not part of the partner Institutions). In this case, we recommend that the candidate register with the Host University and complete their studies from home afterwards (especially for the shorter term mobilities. However if they are registered with a Home University- then they can proceed with studies after the mobility at that particular University- provided the credit transfer systems are agreed upon before the candidate embarks with studies.