You have obviously heard of this :
Kaladan Multi-Modal Transit Transport Project - Wikipedia
The project has many components, but I will only focus on the railway part of it. The initial plan was to connect Mizoram to Myanmar by rail then use the Sittwe port of Myanmar, which again we are developing, with the Kolkata port. Now the connectivity will be done using multiple means(road, rail, inland waterways and later air) to bring a degree of redundancy. The problem was Mizoram doesn't have a broad gauge rail track yet, the sad state of infrastructure in NE.
So Delhi is left with 2 choices :
1. Build a new broad gauge track in Mizoram.
2. Use the nearest state with broad gauge i.e. Tripura.
Delhi chose do do both. Mizoram will get a broad gauge by 2021 :
Mizoram to have broad gauge rail line by 2021: Amit Shah
And an alternate path though Tripura. A road-rail combined bridge connecting Belonia in South Tripura with Parshuram, Bangladesh. Now, it was originally planned that this bridge will eventually lead to a Bangladeshi port(Chittagong port, I think) which was to be a substitute to the Sittwe port, in case the deal with Myanmar doesn't go through.
Now here comes the politics. Tripura is not geographically at the border of Myanmar but has always wanted a connection to Myanmar. Why ? Because then we can use that to connect to Thailand and all the way to Vietnam. Its far fetched, I know. Its an old dream of people who don't have the means to achieve such dreams. Sort of like "Ghazwa e hind", I guess.
To get a background of this "dream" read this old article :
State demands 257 kms railway track from Tripura to Myanmar border
The Agartala-Bangladesh lines are being built as we speak. Construction has progressed quite a bit, tracks are being laid at a few places, bridges being built. The Agartala railway station needs to be expanded to handle international traffic. Then there are other things like customs, passports etc. so expect delays in implementation. But construction is proceeding well.
The Belonia-Myanmar line is something GoI is discussing with the Bangladeshis. I suppose the Bangladeshi govt. wants to keep quiet about this given their ongoing spat with Myanmar regarding the Rohingya situation. Delhi is in a bind in a way, we can't overtly support Bangladesh lest we might cause problems for the India-Myanmar relations and vice versa. Both Bangladesh and Myanmar seem to want to use India to needle each other. Scenes straight out of a soap opera. Lovely isn't it ?
As for tracks, they are the same everywhere. Call it the vestiges of the British empire. The only problem is narrow gauge and broad gauge.
The Tripura govt. is confident the link through Bangladesh is happening, but they also seem to strongly believe the Myanmar link will also happen. We seem to be developing an "industrial" policy around it, if you want to call it that. The plan is make stuff in South Tripura and sell it to the world, make stuff in North Tripura and sell it to India, West Tripura is the administrative block and East Tripura has tourists spots.
Tripura gets its first-ever SEZ
Its ambitious, no doubt. There are a lot of roadblocks. But the political leadership of the state seems to think it will work. When asked about the problems that might arise in the train/road/railway links with Bangladesh and Myanmar given the Rohingya and the NRC in Assam, a senior politician from BJP said : "Delhi will find a way".
I have no faith in CM Biplab Kr. Deb, but I do hope Delhi knows how much of our hopes are riding on them.
I seem to have gone off topic, alright I will stop now.