
Aurghyadip Kundu hm... the matter is a bit confusing.. 'cause it can also be sodium hexanitritocobaltate(III)
it is sodium hexanitrocobaltate(|||) where cobalt is the central metal ion in the coordination sphere and the 6 NO2 r the ligands each joind by a coordination bond
Sodium heanitro cobaltate (III)

sorry there was a typing mistake
I omitted the'x' from "hexanitro"