The Preamble to the Constitution of India is

The correct option is "a part of the Constitution but has no legal effect independently of other parts."

To understand why this option is correct, let us analyze the legal status and significance of the Preamble to the Constitution of India through key judicial pronouncements by the Supreme Court of India:

1. Is the Preamble a part of the Constitution?
Yes, the Preamble is an integral part of the Constitution. This was established through major judicial decisions:
- In the Berubari Union case (1960), the Supreme Court initially held that the Preamble was not a part of the Constitution.
- However, in the landmark Kesavananda Bharati v. State of Kerala case (1973), the Supreme Court rejected the earlier view and ruled that the Preamble is indeed a part of the Constitution. This position was further reaffirmed in the LIC of India case (1995).

2. Does the Preamble have legal effect independently of other parts?
No. While it is a part of the Constitution, the Preamble has two key limitations regarding its enforceability:
- It is non-justiciable, meaning its provisions are not directly enforceable in a court of law.
- It is neither a source of power to the legislature nor a prohibition upon the powers of the legislature.
- It acts as an introductory guide to interpret other articles of the Constitution. Therefore, it does not have any legal effect or utility when read completely on its own; its legal significance arises only when read in conjunction with (or dependently on) other specific, operational articles of the Constitution.

Thus, the Preamble is a part of the Constitution, but it has no legal effect independently of other parts.