The choice really comes down to what you are looking for from your car, and without knowing that its hard to pinpoint one. If you drive mainly in the city, we would rule out the Harrier. It is quite large, and though the steering on the petrol is light, on the whole, the car does not really feel nimble on its feet. 

It is best for highways and longer drives. Between the Tata Sierra and the Hyundai Creta, the Sierra has the advantage of newness and novelty value. You will also get more equipment, like a three-screen setup, a better-sounding audio system and a powered tailgate. However, you will have to pay more than Creta. Thus, if your budget is strict, then the Hyundai Creta will prove to be a very good all-rounder. 

The choice of car really comes down to what you are looking for, without knowing this its hard to pinpoint one. If you drive mostly in the city, the Harrier would not be a good option. It is large, and even though the steering is light, the car does not really feel nimble. It is best suited for highways and longer drives. 

Between the Tata Sierra and the Kia Seltos, the Sierra has the more classical good looks, and you will also get more equipment like a three-screen setup, an air-purifier, a better-sounding audio system and a powered tailgate. However, you will have to pay more than the Seltos. Thus, if you are strict with your budget, then the Kia Seltos will be a good all-rounder. 

If you are buying a petrol automatic, the Tata Sierra makes more sense if mileage, features and lower running costs are your priority. Its smaller 1.5 litre turbo petrol engine and overall size should make it more efficient. You also get a more feature-rich cabin at a lower price, as the two sit in different segments.

The Mahindra XUV 7XO suits buyers who want a more traditional SUV feel with stronger road presence and a proven mechanical package. Its powerful 2.0-litre turbo petrol engine delivers more effortless performance. But the petrol automatic will be less efficient and costlier to run. If long term reliability and established credentials matter more, the XUV 7XO is the safer bet.

Of the two cars you've suggested, and given your requirements, we would recommend the new Kia Seltos. 

For one, you'll find it a more natural upgrade from your Hyundai Venue 1.0 Turbo DCT, as both cars come from the same Hyundai Group family and use related hardware. That being said, the Seltos is built on a new-gen platform called K3 and comes with far more advanced tech. Especially when it comes to the infotainment system and connectivity. 

Because the Seltos engines are unchanged from before, we know what to expect from them - whether the 1.5 naturally aspirated petrol or the 1.5 turbo petrol. Since your driving is 60% city, we would stick with the 1.5 petrol IVT, as it is the smoother and more efficient powertrain overall. 

Kia, like Hyundai, tends to be reliable in the long run - as you've no doubt seen with your Venue - and maintenance costs are reasonable too. The Tata Sierra has promise, but its all-new engines are as yet unproven, and in our experience. While its 1.5 turbo petrol is smooth and powerful, the 1.5 naturally aspirated petrol feels underpowered in this size of car.

The new Tata Sierra has a strong air conditioner that cools its large cabin rather quickly. This is despite its large glass area, created by its huge panoramic sunroof. This is true of the second row, too, where the upward-tilted central AC vents do well to direct air to passengers. 

Rear seat passengers have class-best space and comfort, too. Thanks to the immense leg room, headroom, and width. The Tata Sierra has a large boot as well, which will easily take a full-size golf bag.