As held by the Hon'ble Supreme Court in Hindustan Antibiotics Ltd. Vs. The Workmen that though in fixing the pay structure of the public corporations, due regard should be had to the pay structure in the civil services, the same was only advisory in nature and did not mean that the wage structure of the public corporations should be of the same pattern obtaining in departments of the Government. It was further held that the service conditions of employees in public sector undertakings are not analogous to those of the Government employees; there is no security of service; the fundamental rules do not apply to them; there is no constitutional protection; there is no pension; they are covered by service standing orders; their service conditions are more similar to those of employees in the private sector than those in Government departments. In such circumstances, the question of violation of Article 14 of the Constitution of India does not arise as that arises only if the persons are similarly placed. Article 14 does not apply in a vacuum. The equality clause contained in Article 14 will have no application where the persons are not similarly situated or when there is a valid classification based on a reasonable differentia.

If there is no constitutional protection for CPSE employees does it mean that management of the CPSE is free to discriminate on payment of allowances with unreasonable classification? e.g.
The payment of HRA has no relation to definition or Constitution of the family. But one of the CPSE allows retention of House or payment of HRA to married employee on transfer and provides him with bachelor accommodation at new place of posting. But in case of a bachelor employee they say you can not retain house or claim HRA on provision of bachelor accommodation. The case relating to violation of article 14 of the constitution will not be entertained? The payment of allowance like HRA does not depend on the definition or constitution of the family then is it correct to classify employees on the basis of marital status?  Will it be a reasonable classification?

Unfortunately the Supreme Court or any court in the world is not infalliable. If you read read this you will get an idea of the things  http://en.wikipedia.org/wiki/Supreme_Court_of_India#Emergency_and_Government_of_India It becomes most unfortunate if the judges and their judgements are coloured with personal biases and prejudices. Courts need to follow a formula that eliminates any arbitrariness or caprice in deciding cases. After all what is the point of having a guarantee of fundamental rights in the Constitution and having the Supreme Court and High Courts to safegaurd them, if cases related to fundamental rights are to be adjudicated on some loose or vague criterion?

Extract of Article 12 of the Constitution of India:“12. In this Part unless the context otherwise requires, ‘the state’ includes the Government and Parliament of India and the Government and the Legislature of each of the States and all local or other authorities within the territory of India or under the Control of the Government of India”

It may be noted that the Supreme Court of India has held in number of decisions that Public Corporations and Undertakings fall within the inclusive definition of “State” as defined in Article 12. Therefore these corporation and undertakings are subject to Part III of the Constitution. Consequently the Supreme Court and High Courts have power of judicial review under Article 32 and 226 of the Constitution. The Supreme Court has interfered with the orders of Public Corporations and Undertakings in relation to service matters and also with regard to commercial transactions.

Any organization which is controlled by the State or Central Government, either directly or indirectly, is called state owned organization. If the government invests in the share capital and holding more than 50% shares, this is called State owned / controlled organisation. Central Public Sector Enterprises (CPSEs) are those companies in which the direct holding of the Central Government or other CPSEs is 51% or more.

One may find vested and undemocratic interests try their best by doing all kinds of casuistic reasoning possible to discredit the Strict Scrutiny but the fact remains that some rights are so fundamental that they are not open for "go with the wind" or other kinds of similar ideas and need to be always protected, and especially from the State action. That is why they have been guaranteed in Constitution as fundamental rights because State likes to infringe such rights. Therefore instead of subjecting to loose and vague standards of judicial reviews like "reasonable" restrictions or proportionality analysis etc., the most strict form of judicial review i.e. doctrine of strict scrutiny is to be applied while adjudicating about violation of fundamental rights by State. Strict Scrutiny is a powerful analytical tool for the review of State action that is why vested and undemocratic interests fear it. One can read about Strict Scrutiny judgements at http://lawandotherthings.blogspot.in/2009/08/justice-sinhas-final-attem pt-to-clear.html

The doctrine Strict Scrutiny has been created to arrive at an outcome determinative rule like standard in constitutional adjudication which could discipline judicial discretion. The principle of strict scrutiny flows from the equality and equal protection clause of Article 14 of the Constitution. Once a court determines that strict scrutiny must be applied, it is presumed that the law or policy is unconstitutional. To pass strict scrutiny, the law or policy must satisfy three tests:

1) Burden on State to prove that there is compelling State interest.

2) Burden on State to prove that the law or policy is narrowly tailored to achieve that goal or interest.

3) Burden on State to prove that the law or policy is the least restrictive means for achieving that interest.

May also read this related discussion http://www.lawyersclubindia.com/experts/Is-it-discrimination-or-inequality-before-law—251381.asp