Between the three cars you have shortlisted, the Tata Sierra Adventure Plus is the nicest, especially because of its turbo-petrol engine and torque converter (automatic) combination. Its powertrain will feel smooth, refined and powerful, good for city and highway driving, both.
The Kia Seltos turbo’s dual-clutch automatic can feel a bit jerky at low speeds or in bumper-to-bumper traffic conditions. If your usage is mainly in the city, opt for the 1.5L petrol-IVT instead, which is a far smoother option.
Since you have the budget, and don’t mind opting for a larger car, we’d rule out the Mahindra XUV 3XO as the Sierra Turbo-AT or Seltos 1.5 Petrol-IVT deliver a more premium overall experience.