A petrol hatchback that is a good base car to tune.
Well, when tuning comes into the picture, its usually good to go in for a Japanese Car. The reason being the huge aftermarket arena that sell performance parts for these vehicles.
From the present set of cars available in the market, there can be different ways to go about it. This is purely my opinion though.
One would be to go with something like a Alto k10. The car is already a pocket rocket. 0-100 in about 13.3 seconds if I am not mistaken. High speed maneuverability though comes as a issue. But with a little bit of an effort things can be sorted out. A lovely little engine to start working on I would say. The advantage of a k10 would be that the initial cost will be lesser. A little more forgiving on the pocket overall.
Second option I would say is the Honda Jazz. The word vtec just reminds me of the old Honda Citys. Its not the same engine but it is still a free revving engine which is loads of fun. Again a good start off point.
Third option, I would say would be the Maruti Swift. Umpteen examples of well modified Swifts are out there.
So i guess to sum it up. It all depends on how much you are willing to spend, initially and later on for mods. What type of hatch you looking for, in the sense something for you alone or something for the family, something that does city rounds or is also needed to carry some luggage and go on long drives.