Well, first of all, Assura RCX is an outdated or deprecated extraction tool.
It was replaced by QRC then Quantus, by Cadence.
Quantus QRC can extract inductances, but you need to tell it explicitly (via commands) that you want to extract inductance.
It offers several inductance extraction modes - RLC and RLCK, where L is self-inductance, and K is mutual (coupling) inductance.
Since there is no shielding or screening from magnetic field (unless your circuit is superconducting, of course), every current filament (i.e. every parasitic resistor) is coupled to every other filament (resistor).
Hence, the size of the netlist will become huge, and post-layout netlist will be impractical to use, for circuit simulations.
Quantus QRC allows to do some fine-tuning of the input setup, to reduce the size of the netlist.
Please refer to Quantus QRC user manual, for further details.