not recommended. You are not supposed to expose the rebar in any way 

  not understand.
Just drill small hole like hanging picture type (dia 6mm, depth 2inch) can expose the rebar???

Like some of the others mentioned, it really depends on your building management people. They will eventually have the final say - of course - you can still do it 'secretly' and not mention the doorway as your plans but interior renovation when you fill in the form for permission for your contractor to initiate work.

when we say a support wall cannot hack, does this mean small hacking for concealed wires also not allowed?

what about drilling a small hole to add a power socket right beside an existing socket?

ok, but play safe plan a 2nd route which is more inconvenient.

those walls that are part of exterior wall of building, also can do minor hacking for wiring?

cause it's all hacking whether big or small was told cannot hack support walls but never mention big hack or small hack.

also is it ok to drill a small hole tru the support wall to route a wire pass it? any consideration of the hole location, like cannot too close to the wall/ceiling?

the 1st route would be ideal unless structural integrity is a concern, if by 2nd route will be longer route, more hacking and certain locations i could not put the sockets without using exposed routing.

what about drilling a small hole for a Cat6 cable to pass, is it ok? coz no other way other than drill a hole tru the window which is not ideal.