Kia Carens Clavis

Since your priority is third row space, it would come down between the Maruti Suzuki XL6 and the Kia Carens Clavis. The Hyundai Alcazar does have a third row, but it isn't as roomy as the other two. 
The Kia Carens Clavis has the edge when it comes to features and equipment, a plush cabin with a premium feel and a more powerful engine.

However, the XL6 is an excellent value considering what it offers for the price. If you seek performance and features and don't mind paying extra, the Clavis is a very good choice.

However, if you can make do without the jazzy interior and want a predominantly spacious third row, the XL6 would be a good choice. 

You should consider getting the Kia Carens Clavis. It's got a comfy and spacious cabin that can be had in 6 or 7 seater forms, and it comes loaded with features. 

The Carens Clavis comes with three engine options - a 115hp, 1.5-litre naturally aspirated petrol, a 116hp, 1.5-litre diesel and a 160hp, 1.5-litre turbo-petrol. Since your yearly running isn't very high, consider getting one of the petrols. 

Currently, there are two models that fit your requirements - the Maruti Suzuki Ertiga and the Kia Carens Clavis. Both have spacious cabins that are reasonably comfortable for seven passengers, and both come with naturally aspirated 1.5-litre petrol engines. 

The Ertiga, however, will be more fuel efficient and, being a Maruti car, it'll also come with a stress-free ownership experience. The Kia car, on the other hand, offers many more features, and it can even be had with either a 1.5-litre turbo-petrol or 1.5-litre diesel engine options.   

While both the Mahindra XUV 700 and the Kia Carens Clavis are seven-seaters, their strengths are quite different. The Mahindra car is larger with a more powerful engine and a comfortable ride, and in the top AX7L variant, it is packed with features. Fuel efficiency is not its strong point in either petrol or diesel, and the third row is not ideal for long journeys.

The Kia Carens Clavis is more affordable with more efficient engines and is a better seven-seater. Thanks to a roomier and more comfortable third row. It is well-equipped too. However, while its engines are adequate, it does not feel as effortless or punchy as the XUV 700.

Your final choice should depend on what you prioritise. If you are leaning towards the XUV 700, it may be worth waiting as the facelift is expected soon with more features and updated styling.

Given that you still want a three-row MPV, you should consider the Kia Carens Clavis. 

This Kia car has a spacious and practical interior, it's feature-packed, and what's nice is that passengers will be comfortable in all three rows of seats. 

The Carens Clavis can be had with a 115hp, 1.5-litre petrol, a 160hp, 1.5-litre turbo-petrol and a 116hp, 1.5-litre diesel engine options. However, given that your yearly running is high, it's best to opt for the diesel, which can even be had with a 6-speed torque converter automatic gearbox for greater convenience.