Give oxidation number of cobalt in the given compound and IUPAC name also..?

Dear student

[Co(Cl)(NO₂)(NH₃)₄]ClO₄

​The compound exists as :
[Co(Cl)(NO₂)(NH₃)₄]⁺ClO₄ ^-
So, let the oxidation state of Co be x
then : x+(-1) +(-1)+ 4x 0 =+1 [ oxidation state of Cl is -1,  NO₂ is -1, and NH₃ is 0]
so x -2 =+1
x = +3

The IUPAC name is : Tetraamminechloronitro cobalt (III) perchlorate

​Regards