Hyperloop Transportation Technologies (HTT) is looking to target India as a market for its revolutionary new high-speed passenger transport system, which is based on an idea conceived by Elon Musk.
The interesting thing about this technology is that compared to maglev bullet trains, this offers higher speeds - and at one-tenth the cost. The reason is that maglev bullet trains work on magnetic levitation and require expensive superconductive magnets to be laid out all along the entire track. Meanwhile, the hyperloop approach uses such magnets to accelerate out of the train station, as well as to decelerate it when arriving at the destination station, but in between the starting and stopping points it's mainly just cheap plastic tubing, since the traincar/pod is being propelled by an airflow like an air-hockey puck or those old pneumatic message tubes.
The problem of course is that the idea is still in development and has yet to be validated as an actual functioning mass-transportation system.