The court cannot proceed with an assumption that the legislature enacting the statute has committed a mistake and where the language of the statute is plain and unambiguous, the court cannot go behind the language of the statute so as to add or subtract a word playing the role of a political reformer or of a wise counsel to the legislature.
The court has to proceed on the footing that the legislature intended what it has said and even if there is some defect in the phraseology etc., it is for others than the court to remedy that defect. The statute requires to be interpreted without doing any violence to the language used therein.
No word in a statute has to be construed as surplusage. No word can be rendered ineffective or purposeless. Courts are required to carry out the legislative intent fully and completely. While construing a provision, full effect is to be given to the language used therein, giving reference to the context and other provisions of the Statute. By construction, a provision should not be reduced to a “dead letter” or “useless lumber”.
An interpretation which renders a provision an otiose should be avoided otherwise it would mean that in enacting such a provision, the legislature was involved in “an exercise in futility” and the product came as a “purposeless piece” of legislation and that the provision had been enacted without any purpose and the entire exercise to enact such a provision was “most unwarranted besides being uncharitable.” 
The Court in Rohitash Kumar & Ors. v. Om Prakash Sharma & Ors., AIR 2013 SC 30, after placing reliance on various earlier judgments of the Court held:
“The Court has to keep in mind the fact that, while interpreting the provisions of a Statute, it can neither add, nor subtract even a single word… A section is to be interpreted by reading all of its parts together, and it is not permissible, to omit any part thereof. The Court cannot proceed with the assumption that the legislature, while enacting the Statute has committed a mistake; it must proceed on the footing that the legislature intended what it has said; even if there is some defect in the phraseology used by it in framing the statute, and it is not open to the court to add and amend, or by construction, make up for the deficiencies, which have been left in the Act……
The Statute is not to be construed in light of certain notions that the legislature might have had in mind, or what the legislature is expected to have said, or what the legislature might have done, or what the duty of the legislature to have said or done was. The Courts have to administer the law as they find it, and it is not permissible for the Court to twist the clear language of the enactment, in order to avoid any real, or imaginary hardship which such literal interpretation may cause…….under the garb of interpreting the provision, the Court does not have the power to add or subtract even a single word, as it would not amount to interpretation, but legislation.”
Hardeep Singh v. State of Punjab (2014)
 Patel Chunibhai Dajibha etc. v. Narayanrao Khanderao Jambekar & Anr., AIR 1965 SC 1457; The Martin Burn Ltd. v. The Corporation of Calcutta, AIR 1966 SC 529; M.V. Elisabeth & Ors. v. Harwan Investment & Trading Pvt. Ltd. Hanoekar House, Swatontapeth, Vasco-De-Gama, Goa, AIR 1993 SC 1014; Sultana Begum v. Prem Chand Jain, AIR 1997 SC 1006; State of Bihar & Ors. etc.etc. v. Bihar Distillery Ltd. etc. etc., AIR 1997 SC 1511; Institute of Chartered Accountants of India v. M/s. Price Waterhouse & Anr., AIR 1998 SC 74; and The South Central Railway Employees Co- operative Credit Society Employees Union, Secundrabad v. The Registrar of Co-operative Societies & Ors., AIR 1998 SC 703).