Vehicles in BeamNG is a very complex thing to create, which is why there isn't 100+ vehicles to choose from, even though the game has been out since 2012/2013. If you read this https://documentation.beamng.com/vehicle_system/index.html you can see a lot of the things that goes into creating a vehicle, and you still have to create the 3d model. You can always give automation a try, they won't crash like stock cars but it's a lot easier to do and fun. tl;dr it's difficult.
Hmm, if you give me a blueprint I may be able to try making a model of it.. I tried making a model of my Renault Logan, but ran out of cpu power and motivation.. might try again sometime..
The Doyler Beagle has an Indian version, that´s probably the closest you are going to get to an Indian car.