9) Add 122 hydrogen ions:
10K4Fe(CN)6 + 598H+ + 122KMnO4 ---> 10Fe3+ + 122Mn2+ + 188H2O + 162KH2+ + 60HNO3 + 60CO2
Note how I combined the potassium ion and hydrogen ion on the right-hand side. There is no such thing as the KH2+ ion. It's an artifical construct used as a placeholder for the potassium and hydrogen ions that will be used to combine with sulfate to make the KHSO4 in the final answer.
10) Add 218 + 81 = 299 sulfate ions:
10K4Fe(CN)6 + 299H2SO4 + 122KMnO4 ---> 5Fe2(SO4)3 + 122MnSO4 + 188H2O + 162KHSO4 + 60HNO3 + 60CO2
On the right, the sulfates are distributed thus: 15 to the iron(III) ion, 122 to the managanese(II) ion and 162 to the KH2+ ion.