The IUPAC name for the complex $\left[\mathrm{Co}\left({\mathrm{NO}}_2\right){\left({\mathrm{NH}}_3\right)}_5\right]{\mathrm{Cl}}_2$ is

As per IUPAC rules, for cationic complexes,
Ligands will be named first in alphabetical order, then the central metal ion along with its oxidation state, then the anion part.
Let, the oxidation state of central metal ion be x

As we know NH₃ is neutral and NO₂ contains −1 charge and Cl contains −1 charge
So, x−1+0−2=0

x−3=0

x=+3

∴Pentaamminenitrito­-N­-cobalt(III) chloride.