The reaction, posted by AWK indeed takes place, but I would not say that Na2SO4 is formed, but NaHSO4 (but that only is a minor detail).
More important, there also is another reaction and the majority of all bromide will end up with this:
H2SO4 + NaBr --> NaHSO4 + HBr
The reaction, mentioned by AWK is a side-reaction. So, in practice, when you add concentrated H2SO4 to NaBr, then HBr will be formed, which is contaminated with SO2 and Br2.
With NaCl instead of NaBr, only HCl is formed, the free halogen is not formed in that reaction.
With NaI instead of NaBr, the majority of the material is oxidized to iodine, SO2 and even H2S being formed from the acid. With NaI, only a small part of the iodide is converted to HI when concentrated sulphuric acid is added.