The Tata Safari and Mahindra XUV 7XO are the best options for your requirements. Both are large SUVs with strong road presence and ample room in the first and second rows. 

However, it's the Tata Safari that has the better third row, with a bit more space and a comfier seating position. If the third row will be used often, we would recommend the Safari. 

The Mahindra XUV 7XO doesn't offer a middle row slide function, leaving no option to free up extra space for third row passengers. The third row is usable but is best for short commutes. 

The Mahindra XUV7XO is a good option to consider. Since your running is high, we would recommend the diesel version, which also delivers well on performance and refinement. Within your budget, you would get a well-specced version like the AX7 or even the AX7 Tech. 

The XUV7XO also rides very well thanks to new tech dampers (DCx) and it's comfortable inside too. The third row is not as spacious as the Tata Safari, but since your usage is mostly 5 and occasionally 6 to 7 people, this should be ok for you.  

Go for the Tata Safari turbo-petrol. It is far more suited as a seven-seater than the Mahindra XUV 7XO, due to a more spacious third row. Also, the Sierra's touchscreen and user interface are far simpler than the Mahindra's, which can feel a bit overwhelming, at least initially.

While we haven't extensively tested the Safari turbo-petrol, expect single-digit fuel efficiency in urban conditions. It is expected of such a large SUV. If running costs matter, then you could consider the diesel version instead. 

Relatively smaller and easier to drive 7-seater options are the Hyundai Alcazar and Kia Carens Clavis, which come with turbo-petrol and diesel automatic options.

Of the two, the Mahindra XUV 7XO is the better pick. The XUV 7XO is packed with tech and is far nicer to drive than the MG Hector, too. Mahindra's engines and gearboxes are highlights, and the 7XO's updated suspension also gives it the edge in ride comfort. Importantly, the 7XO offers a better third-row experience than the Hector Plus. 

That said, the XUV 7XO is not the best 7-seater for the money. Especially in case the third row space and comfort are a deal breaker for you. The Tata Safari offers a more comfortable third row among petrol/diesel SUVs of the segment. 

If you are open to electric, the Mahindra XEV 9S is worth a look. While you could think of it as an all-electric version of the XUV 7XO, the 9S does boast of a better third row. The option to slide its middle row seats makes all the difference to balance second and third row space in the cabin.  

While there are a lot of SUV options that fall within your budget, we've listed the top models worth checking out. Among the monocoque-bodied SUV options, there's Tata's Harrier and Safari, and the Mahindra XUV 7XO. These SUVs are large and have great road presence. Also, being monocoque SUVs, they score well on comfort and refinement. 
 

If you are looking for something more hardcore, there's the option of Mahindra's ladder frame SUVs, namely the Scorpio N and Thar Roxx. These SUVs are big on image and have a toughness about them that's very appealing. 

However, they are not as comfortable as the models listed above. 

The Kia Carens Clavis is the ideal pick for your requirements. It's a well-packaged MPV that offers comfortable seating across all three rows. A one-touch operation for the middle row seat fold makes access to the last row easy. Also, there is ample movement built into the middle row to balance space for all passengers. 

The Clavis is also easy to drive and doesn't intimidate as some three-row SUVs can. From the Clavis line-up, the Turbo DCT HTX(O) is the one to buy.

Of the other three-row petrol-auto options, there's the Hyundai Alcazar, MG Hector Plus, Mahindra XUV 7XO and Tata Safari.