The first number is 0

From Hint 1 & 2, we come to know that the number 6 is the incorrect number.

From Hint 3, we come to know that 2 & 0 are correct numbers.

From Hint 4 & 1, we come to know that number 2 is correctly placed.

Hence the number will be _ _ 2

From Hint 3, 4 & 5 we come to know that 0 is wrongly placed in (2,0,6) & (7,8,0) .

Hence the number will be

(0 _ 2)

And from Hint 2 we come to know that the middle number is 4

Answer = 042