Coal field since its originating and is likely to run on time. Other wise just go to the station at 5 am, take a GEN ticket and board any late running train towards HWH.You will surely find some eats empty of people getting down at DHN or ASN.Just convert your tkt on board. May be you will get a 2 am or a 3 am train which may be running late by 2-3 hrs. Who knows even Rajdhani may run late and why waste money by paying CK 3AC Rajdhani fare and still not reaching on your time.