Alright then.
The mountain range looks to similar to the mountains of the Andes, so I’ll use Aconcagua as a staple.
6960.8 / 387 = 17.9865633 metres
17.9865633 x 573 = 10306.3008 metres or 10.3063008 kilometres
((5.1531504/0.28)^3)/1000 = 6.23367793 Megatons.
We should half that since it was amped by Ha Yusing as well, so we get 3.11683896 Megatons.
Small City level.
This would of course scale to Baam, Ha Yusing and Endorsi but only for the Hidden Floor Arc.