With ICF rakecalso it's doing in 6hrs. Not just these 5 days even before after this timing fixed its doing in 6hrs. Even TN used to do Chennai BZA 5.5 6hrs. It's due to no express trains in front or back for two trains and higher priority. It all depends on that day. Last Friday Coro took 7.15 hrs and reached 1900 though late didn't cover.