I say, let it into GT. We have other lightweight, low-power city cars in the game (Subaru 360, classic Fiat 500s, Mazda Carol, etc.), this would work as a new rival to that class.
Becides there's no cars from India in this game. Beings that this game is all about racing a variety of cars from around the world, why not give this little car a shot.
I would love to do a cup race with these on all the smallest and tightest courses on GT.
If a Race Modified version was also available (retuned engine, Color & Number Changeable), that would be even better.