As per the GST provisions, supply made to each distict person is taxable unless it is an exempted supply of goods and / or services. For Branches inside a state one can have cetralised registration by declaring branch addresses in the registration certificate. In that case one can transfer goods to and from branches inside the state by using E ways only and no need to raise tax invoice for such transfers
However in the case wherein separate registration is sought and in the case of interstate transfer ( any way separate registration would be there for each states of location), supplies made to / from each branches is taxable. Output tax and input tax would be dealt accordingly