the train 12975 starts from bangalore on 07/12/2013 (Sat) and reach hyderabad (kachiguda) on 08/12/2013 (sun) 02.45 AM. so my boarding date from hyderabad to kota is 08/12/2013. so i should book tatkal ticket on 06/12/2013(i.e one day before departure of train). but it is showing not available(i.e. not valid date for tatkal).while if i see bangalore to kota same condition it is showing the availability. So please tell what is the right date to book that ticket.
thank you.