ट्रेनों का सफर, ज़िन्दगी का सफर, रेलफैन दोनों में माहिर

I am planning to do a trip of vaishnodevi and amritsar in may. I am thinking to take JAT-BTI exp from jammu which reaches amritsar at 0205 hrs. I want to cover GT, Jallianwalabagh and wagah border in one day and then catch GT mail to new delhi ( might be tiring or not possible but wanna see the possiblility of this option). Is it possible to attend beating retreat ceremony and catch GT mail, as beating retreat ceremony would end at probably 1830 hrs or 1900 hrs due to summers. And also what are the means to rach wagah border from amritsar city? Are there buses plying between ASR and wagah?

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