You've correctly identified the
Nissan Magnite as the most spacious of your three shortlisted options. Do note, the Nissan's naturally aspirated petrol engine delivers just adequate performance. This will not be an issue in town, but the lack of punch will be felt on highway drives.
Opting for a used option will give you more car for your money, but finding a good quality vehicle takes time. You could use established services to help in this regard. Within your budget of Rs 8 lakh, a well-kept Gen 4
Honda City could be an option worth considering.