I traveled in this train from Guwahati to Agartala in 3AC. The train reaches GHY almost on time. Once you board it, private caterers will come to take orders from you. However, I will advise you not to take food from them. Instead, for food in your journey, you can do the following things.
1. The train reaches Lumding bang on time at 8.45 am. Because of rake reversal the train stop there for 30 mins. You can get down and from that platform, purchase your breakfast. You can also get lunch from Lumding. Dal, Rice and Curry costs Rs. 50. The private caterers also load food from Lumding but they always charge more for the food so it is the cost...
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effective option. If you don't want to get down from the train or have some problems then don't worry about not ordering before. The caterers always have food with them and so you can order later also.
2. After Lumding, the train stops at New Halflong. There you will find freshly cut fruits on sale by local vendors. Do try the papaya which is delicious. However, you will not find rice or other conventional food items there so do be careful
3. Badarpur or Karimganj is the place where you can purchase your evening snacks and tea. Karimganj is a slightly smaller in comparison to Badarpur and they will charge more for tea. However, the tea is really good. Stock up biscuits and other items from those two stations and you will be ready for the final stretch.