This one (4th) was originally allocated to SWR/Bengaluru and the next one (5th) was allocated to SR/Chennai.
Now the 4th one has been diverted to NR, so I don't know if the rest will stay in south India or again be taken by NR. SR can lobby and get one, but SWR will most likely just get ignored.
Second-class...
more... treatment of southern zones, then and now 😒