Whose responsibility is a door on to a balcony?

The frame of the doorway is rusting. The doorway leads to the balcony which is the strata’s responsibility.

To me it looks like the rusty part is outside of my walls. I’ve understood that the interior paint and what’s inside is my responsibilty but outside of that it’s strata.

I’ve had a good read through the strata regs but it’s no clear on the area of door frames. thanks in advance