Since both the branches are in the same state and it is transferred from one branch to another, there is no sale, because there must be two independent persons, one buyer and another seller to constitute sale. Hence there you cannot issue sale bill and collect tax. No question of issue of Tax invoice.
At the same time, since the goods are not moving out the State, it is not an Interstate Stock transfer and hence there is no question of F-Form which comes under the CST Act.
Hence it has to be on a delivery note which will be prescribed in the Delhi VAT Rule. Since the goods are transferred without any change of ownership, the firm can take input tax credit, if the first transferring branch has paid input tax while acquiring it. Also, it shall be a common accounts and returns for both the branches.