This is the commune I am registered under and it's fairly decent as far as administrative…read moremunicipalities go (I have heard a lot of horror stories from expat folks living in 1000 Bruxelles). After you walk in thru main door, look to the right as there is a box to get your number for service. I have always used the "Strangers" aka Foreigners desk service and there is an Asian Lady working at the counter who is super sweet and helpful, and when in line, I always hope I end up at her counter.
There is lots of parking around the building but its quite difficult to find an empty spot so my suggestions would be to use bus or tram to get here. That's where the location of this commune comes up trumps as Tomberg Metro is located underneath the Commune Building and there is also a bus stop around the corner, so easy to get here!