Ora 03 isn't a B-Segment car by strict definition because it's 2 inches longer than the upper limit of what's generally defined a B-Segment. It's on the lower end of C-Segment in terms of length.
In your list, only the Swift and Stonic are B-Segment. In fact the C-HR is almost 1 foot longer than the Stonic so they can't even be compared. Here are the typically accepted ranges of the European car segments.
| Segment | Length |
| ----------- | ------------ |
| B-Segment | 3700-4200mm |
| C-Segment | 4200-4650mm |
| D-Segment | 4650-4900mm |
Notice how the Ora 03 is about 2 inches within the lower bounds of C-Segment and has a large wheelbase, so that's why they claim it as such. Also, it's significantly bigger than Swift and Stonic in all dimensions, and surprisingly it's also slightly bigger than Corolla and Civic in terms of width as well. It's wheelbase also fits within Toyota's TNGA-C platform's range which also underpins Toyota's C-Segment offerings.
| Vehicle | Length | Width | Height | Wheelbase |
| --------- | --------- | --------- | --------- | --------- |
| Ora 03 | 4235 mm | 1825 mm | 1596 mm | 2650 mm |
| Swift | 3840 mm | 1695 mm | 1495 mm | 2450 mm |
| Stonic | 4100 mm | 1760 mm | 1520 mm | 2580 mm |
| C-HR | 4360 mm | 1830 mm | 1538 mm | 2640 mm |
| Corolla* | 4370 mm | 1790 mm | 1435 mm | 2640 mm |
| Civic* | 4549 mm | 1801 mm | 1410 mm | 2736 mm |
*Both Corolla and Civic are the hatchback variants in this comparison, which aren't available in Pakistan. In fact, Civic is more of a lift-back now anyways instead of a hatchback. Of course if you compare it with the sedan variants of both, Ora 03 would be shorter, but then it doesn't make sense to compare a hatchback with a sedan.