Which one is not correct?

The correct answer is Option (3) → 15 ≡ 3(mod 9)

$\text{Check } 27 \equiv 3 \ (\text{mod } 4):\ 27-3=24 \equiv 0 \Rightarrow \text{True}$

$\text{Check } 11 \equiv 56 \ (\text{mod } 9):\ 56-11=45 \equiv 0 \Rightarrow \text{True}$

$\text{Check } 15 \equiv 3 \ (\text{mod } 9):\ 15-3=12 \not\equiv 0 \Rightarrow \text{False}$

$\text{Check } -4 \equiv -114 \ (\text{mod } 11):\ -114+4=-110 \equiv 0 \Rightarrow \text{True}$

$\text{Not correct: } 15 \equiv 3 \ (\text{mod } 9)$