Reasonable Construction 

Reasonable construction follows the principle of ‘Ut Res Magis Valeat Quam Pareat’ which means when the interpretation of the statute is made it should be done in a meaningful and sensible manner. If a statute is having a two interpretation where one is completely vague and absurd and other is perfectly making sense then that meaningful interpretation should be used.

A provision of law cannot be so interpreted where it is made without using common sense. Every word or expression used in an act should receive its natural and fair meaning which was made in accordance with the legislator.

Tirath Singh v. Bachittar Singh

It is only when the language of a statute, in its ordinary meaning and grammatical construction, leads to a manifest contradiction of the apparent purpose of the enactment, or to some inconvenience or absurdity, hardship of injustice, presumably not intended, a construction may be put upon it which modifies the meaning of the words and even the structure of the sentence.

Kanwar Singh v. Delhi Administration, AIR 1965

Courts can depart from the dictionary meaning of a word and give it a meaning which will advance the remedy and suppress the mischief provided the Court does not have to conjecture or surmise. Construction will be adopted in accordance with the policy and object of the statute.

Harmonious Construction 

This rule of interpretation is adopted when there is a conflict between two or more statutes or between two provisions of the same statute. Every law has a certain purpose set, so judges should take those purposes into consideration and it should be read as a whole while interpreting. Judges should apply such provisions which are in accordance with the public interest. The laws which are applied must be consistent and shouldn’t overlap with other existing laws. The courts should avoid using such laws which bring ambiguity to the subject and makes courts inconsistent.

Sometimes it’s impossible to harmonise between two provisions of the statute at that time the decision of the judges will prevail above everything. When there is “a head-on clash” between the provisions of law the judges should bring harmony and make justice to both the parties.

Supreme Court explained harmonious rule as to when the two provisions of the same legislation are inconsistent with each other, both the provisions must be interpreted in such a way where it gives equal importance to others. Here one provision will not override on other provision, it aims at harmonizing between conflicting provisions and avoids destruction one provision.

Supreme Court has laid down five principles of rule of Harmonious Construction in the landmark case of CIT v. Hindustan Bulk Carriers:

1. The courts should avoid such provisions which are contradicting in nature and which brings the head-on clash between each other. 
2. The courts should interpret in such a way that brings harmony to the contradicting provisions.
3. The provision of one section cannot defeat the other provision.
4. When the court fails to bring harmony to both parties, it should at least interpret in such a manner where both the provisions are given effect as much as possible.
5. Courts should keep in mind that the interpretation which reduces one provision to the dead is not harmonious, here harmonising doesn’t mean destroying.

Purposive Construction 

It is the modern version of mischief rule. It is actually more flexible compared to literal rule and golden rule which tends to concentrate more on the meaning of individual words or phrases. This looks for the purpose of the law. This rule allows judges to add or ignore any of the words in the statute while interpreting in order to protect the purpose of creating that law and give fair and equal justice to everyone. 

This rule is always compared with the mischief rule. As mischief rule looks into the gap between the old and new law and how parliament came up with the new law and what are the new remedies brought out to resolve the problems which were exiting before, whereas the purposive construction rule is broader where it not only figure out the gap between the old and new laws but it also helps judges to make an attempt to identify what parliament meant to achieve.

The days have passed by when judges used to use only strict rule where they interpret the law only based on the meaning of the words used in the statute, but now court seeks to give effect to the purposive rule where it not only consider the words of the statute according to their meaning but also according to the context. ‘Context’ here doesn’t mean only ‘linguistic context’, it takes into consideration the subject-matter, scope, purpose, and background of the act. 

Important features:

1. Here judges do not go by the letter of the law, but they look into the intention and the spirit of the statute.
2. Legislative intention is a fictitious concept.
3. The legislative intention with respect to a particular statute can be an intention of the majority of the parliamentarians. 
4. In mischief rule, the court resorts a particular act intended to remedy but purposive construction looks into the overall intention of the parliament on the statute. In this way, purposive construction is wider than the mischief rule. 

Regina V Barnet London Borough Council, Ex Parte Shah

In this case, there were five students who were immigrants came to London for the purpose of studies. They challenged the refusal to allow them grants for their education.

The court held that the House construed the expression ‘ordinarily resident’ in the 1962 and 1980 Acts. Long-standing authority on the meaning of the expression was referred to. The natural and ordinary meaning of ordinary residence had been settled by two tax cases. At least for educational purposes, ‘ordinary residence’ did not include a person whose residence in a particular place or country was unlawful.