Section 11 in The Indian Contract Act, 1872
Title: Who are competent to contract.
Every person is competent to contract who is of the age of majority according to the law to which he is subject1, and who is of sound mind and is not disqualified from contracting by any law to which he is subject.
1. See the Indian Majority Act, 1875 (9 of 1875).
Title: What is a sound mind for the purposes of contracting.
A person is said to be of sound mind for the purpose of making a contract, if, at the time when he makes it, he is capable of understanding it and of forming a rational judgment as to its effect upon his interests.
A person who is usually of unsound mind, but occasionally of sound mind, may make a contract when he is of sound mind.
A person who is usually of sound mind, but occasionally of unsound mind, may not make a contract when he is of unsound mind.
(a) A patient in a lunatic asylum, who is at intervals of sound mind, may contract during those intervals.
(b) A sane man, who is delirious from fever or who is so drunk that he cannot understand the terms of a contract, or form a rational judgment as to its effect on his interests, cannot contract whilst such delirium or drunkenness lasts.
Title: "Consent" defined.
Two or more persons are said to consent when they agree upon the same thing in the same sense.
Title: "Free consent" defined
Consent is said to be free when it is not caused by—
(1) coercion, as defined in section 15, or
(2) undue influence, as defined in section 16, or
(3) fraud, as defined in section 17, or
(4) misrepresentation, as defined in section 18, or
(5) mistake, subject to the provisions of sections 20, 21 and 22.
Consent is said to be so caused when it would not have been given but for the existence of such coercion, undue influence, fraud, misrepresentation or mistake.
Title: "Coercion" defined.
"Coercion" is the committing, or threatening to commit, any act forbidden by the Indian Penal Code (45 of 1860) or the unlawful detaining, or threatening to detain, any property, to the prejudice of any person whatever, with the intention of causing any person to enter into an agreement.
Explanation.—It is immaterial whether the Indian Penal Code (45 of 1860) is or is not in force in the place where the coercion is employed.
A, on board an English ship on the high seas, causes B to enter into an agreement by an act amounting to criminal intimidation under the Indian Penal Code. (45 of 1860).
A afterwards sues B for breach of contract at Calcutta.
A has employed coercion, although his act is not an offence by the law of England, and although section 506 of the Indian Penal Code (45 of 1860) was not in force at the time when or place where the act was done.