My parents are coming to Kota from Hatia (ranchi) via Delhi. They want to reside in Delhi for a day. Can they do break journey. They will be boarding Jharkhand swarna jayanti express/ garib rath most probably. Please suggest the trains from Delhi also. And is it a rule that if a passanger is travelling in Sl in 1st half of jpurney then they have to travel in SL only in 2nd half?