either it will run few hr before the original train or after... for ex u have WL 312 in Poorva Exp(HWH-NDLS) & RB decide to clone Poorva Exp & duplicate one will run 2 hr before the original one.. at the morning u get to know that ur tkt gets cnf in clone train all of nowhere... Would it possible to rush to stn & catch the train.. Since its a cnf tkt if u dont want to travel u wont get a single penny... so now Railway will force u travel or loose the money.,.. good business from their side...
Better the might ask the pax if they would like to travel by the clone one or not. If...
more... not then full fare must be refunded...
also it gets delayed & pax boarding at intermediate stn will be confuse whether its the original one or cloned one... total confusion