Which group P-block elements show highest positive oxidation state?

P-block element of group-16 is sulphur having electronic configuration $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^4$ and exhibits oxidation states - $2,8,6$

P-block element of group-17 is chlorine having electronic configuration $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^5$ and exhibits oxidation states - $2,8,7$

P-block element of group-18 is argon having electronic configuration $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^6$ and exhibits oxidation states - $2,8,8$

P-block element of group-15 is phosphorous having electronic configuration $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^3$ and exhibits oxidation states - $2,8,5$

From the above data, we can conclude that group-18 (Noble gases) will form highest  oxidation states when they form compounds with electronegative atoms like fluorine  and oxygen.