You should have rounded up to 6.03.
If you round to two decimal places, you look at the third:
0-4 means cut off (or round down) second decimal stays the same
5-9 means the second decimal place goes up.
As you know, when doing standard rounding to a certain decimal place, we look at the digit before that decimal place and decide whether or not we should round up or down. In this case, the digigt before the second decimal place is 8. Because this number is more than five, we round up.
As a general rule, if a certain decimal is called "x", then we round as follows (with the arrows indicating rounding up or down):