Indigo car has some refinement issues. My friend had to take it initially sometimes to get this nagging issues sorted out. They did it pretty fast without charging him anything for that. Some of the problems he has faced are:
1. Water leaking onto the mats while A/C is on
2. Some body parts creating rubbing sounds
3. A/C idler went bust after 3 years
4. Due to the vibration, the diesel pump clamp had broken off
5. Bearing was damaged after only 3 years
The last one was because they had not put grease during the service. You cannot believe them, you will have to be a bit wary. This I think is the case with all car dealers - not just Tata. When you take for a service, they will come up with all nonsense repairs to be done. It will be around 2000 on an average for the service, even if it is free service. Talk to them in detail about the work you want them to do, when you take the car for service; otherwise, they will milk you.