A consent is not such a consent as is intended by any section of this Sanhita,––
(a) if the consent is given by a person under fear of injury, or under a misconception of fact, and if the person doing the act knows, or has reason to believe, that the consent was given in consequence of such fear or misconception; or
(b) if the consent is given by a person who, from unsoundness of mind, or intoxication, is unable to understand the nature and consequence of that to which he gives his consent; or
(c) unless the contrary appears from the context, if the consent is given by a person who is under twelve years of age.
Legal Commentary & Landmark Judgments: Section 28
Section 28 defines what does NOT constitute valid consent under the Sanhita, establishing that consent is vitiated if given under fear of injury, misconception of fact, or by reason of unsoundness of mind, intoxication, or by a child under twelve years of age.
In Section 69 BNS prosecutions, defense counsel must establish that the engagement was genuine when made: lead evidence of joint matrimonial shopping, meetings between elders, and subsequent unexpected disputes to prove absence of 'misconception of fact' under Section 28.