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.

Since you are very tall, we would recommend the Tata Sierra as it will offer you sufficient head and legroom too. Stay away from the naturally aspirated petrol engine as the performance is weak. Instead, opt for the turbo direct injection petrol engine as it offers a strong and seamless power delivery, which will make overtaking on highways easy. If your running is very high, you could also opt for the diesel, which delivers a reasonably good performance. 

As always, we would recommend you check out the car, especially to see if you are comfortable inside, as besides personal preferences in terms of seating posture, position and even body ratio can make a big difference to roominess.  

Since you already own a Maruti Grand VItara, the Victoris won't feel too different, as both these cars are based on the same platform and have a lot in common, including their powertrains. Hence, if you are looking to upgrade, the Tata Sierra is definitely a better choice. Its interior is more spacious with nicer quality of materials used, and ride comfort is outstanding. Also, the turbo-petrol AT configuration is smooth, refined and delivers strong performance.

We would agree with your pick of the Tata Sierra. The SUV does look very good, and comfort levels are very high with ample interior space, comfortable seats and excellent ride quality. So, this will perfectly meet your two main requirements. Your monthly running of 20 kms is very low, so you can avoid the diesel and opt for the petrol.

However, bear in mind the Pur + variant comes with the naturally aspirated petrol engine, which is a very sluggish performer. Refinement is good, though, and the manual gearbox is light and easy to use.