377. Appeal by the State Government against sentence.

(1) Save as otherwise provided in sub-section (2), the State Government may in any case of conviction on a trial held by any Court other than a High Court, direct the Public prosecutor to present an appeal to the High Court against the sentence on the ground of its inadequacy-
(a) to the Court of session, if the sentence is passed by the Magistrate; and
(b) to the High Court, if the sentence is passed by any other Court”;
(c) in Sub-Section (3), for the words “the High Court”, the words “the Court of Session or, as the case may be, the High Court” shall be substituted.

(2) If such conviction is in a case in which the offence has been investigated by the Delhi Special Police Establishment, constituted under the Delhi Special Police Establishment Act, 1946 (25 of 1946), or by any other agency empowered to make investigation into an offence under any Central Act other than this Code, the Central Government may also direct the Public Prosecutor to present an appeal to the High Court against the sentence on the ground of its inadequacy.

(3) When an appeal has been filed against the sentence on the ground of its inadequacy, the High Court shall not enhance the sentence except after giving to the accused a reasonable opportunity of showing cause against such enhancement and while showing cause, the accused may plead for his acquittal or for the reduction of the sentence.

(4) When an appeal has been filed against a sentence passed under section 376, section 376A, section 376AB, section 376B, section 376C, section 376D, section 376DA, section 376DB or section 376E of the Indian Penal Code, the appeal shall be disposed of within a period of six months from the date of filing of such appeal.
[Criminal Law Amendment Act, 2018]

Comments:
It would be clearly violative of Article 21 of the Constitution of India to induce or lead an accused to plead guilty under a promise or assurance that he would be let off lightly and then in appeal or revision to enhance the sentence;
State of Karnataka v. Benoy Thomas, (1997) 2 Crimes 141 (Kant)

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