answer :
10 HNO3 + I2 = 2 HIO3 + 10 NO2 + 4 H2O
steps
HNO3 + I2 = HIO3 + NO2 + H2O
wikihow
list all elements & number on each side then
match the number
H 1 -> 2
N 1 -> 1
O 3 -> 6
I 2 -> 1
I 2 -> 2 by having 2HIO3
H 1 -> 4
N 1 -> 1
O 3 -> 9
I 2 -> 2
H 4 -> 4
N 1 -> 1
O 9 -> 9
I 2 -> 2
by having