It looks correct now!

I believe there's an error in the sample tests:

Test.assertEquals(validatePIN("123456"),false, "Wrong output for '1234567'")

It's asserting that 123456 should be false while 123456 is actually a 6-digit PIN code. Looking at the error message, I think the author wanted to assert 1234567 and not 123456.

If you have the right solution, you could be failing the TEST but passing ATTEMPT.