Step 1: Evaluate each statement about the Supreme Court.
Option 1 is correct: the SC is the custodian of the Constitution. Option 2 is correct: SC judgments are final with no further appeal. Option 3 is correct: Article 124 establishes the Supreme Court.
Step 2: Examine Option 4.
Option 4 states that a citizen cannot directly approach the Supreme Court for enforcement of Fundamental Rights. This is incorrect: under Article 32 of the Constitution, every citizen has the right to move the Supreme Court directly for enforcement of Fundamental Rights, and this right itself is a Fundamental Right.
Step 3: Identify the incorrect statement.
Option 4 is the incorrect statement about the Supreme Court of India.
\[ \boxed{\text{A citizen cannot directly approach the Supreme Court for enforcement of Fundamental Rights (incorrect)}} \]