To keep it simple,
To restrict people who turn against the security of the country, this law will be charged against the persons who threat the unity, security of the country with their works, words or actions.
124A. Sedition Whoever, by words, either spoken or written, or by signs, or by visible representation, or otherwise, brings or attempts to bring into hatred or contempt, or excites or attempts to excite disaffection towards, the Government established by law in India, shall be punished with imprisonment for life, to which fine may be added, or with imprisonment which may extend to three years, to which fine may be added, or with fine.
Explanation 1. — The expression “disaffection” includes disloyalty and all feelings of enmity.
Explanation 2. — Comments expressing disapprobation of the measures of the Government with a view to obtain their alteration by lawful means, without exciting or attempting to excite hatred, contempt or disaffection, do not constitute an offence under this section.
Explanation 3. — Comments expressing disapprobation of the administrative or other action of the Government without exciting or attempting to excite hatred, contempt or disaffection, do not constitute an offence under this section.
Actually Section 124A of IPC came into existence in the colonial period (1898) to take actions against the freedom fighters. Congress after the independence planned to remove this act as it is against the freedom and liberty of a citizen, but no action taken in this regard.
Gandhi speaking about the section, “Section 124 A, under which I am happily charged, is perhaps the prince among the political sections of the Indian Penal Code designed to suppress the liberty of the citizen. Affection cannot be manufactured or regulated by law. If one has no affection for a person or system, one should be free to give the fullest expression to his disaffection, so long as he does not contemplate, promote, or incite to violence. But the section under which mere promotion of disaffection is a crime. I have studied some of the cases tried under it; I know that some of the most loved of India’s patriots have been convicted under it. I consider it a privilege, therefore, to be charged under that section. I have endeavored to give in their briefest outline the reasons for my disaffection. I have no personal ill-will against any single administrator, much less can I have any disaffection towards the King’s person. But I hold it to be a virtue to be disaffected towards a Government which in its totality has done more harm to India than any previous system. India is less manly under the British rule than she ever was before. Holding such a belief, I consider it to be a sin to have affection for the system.”
In the Kedar Nath Singh case, SC says the section 124A contravenes the article 19 of the COI. Taking the argument forward, SC also questioned the purpose of the section; does s. 124A enact a law which is in the interest of public order and does this section impose reasonable restrictions in the interest of public order.
Law Commission said the law should remain the IPC, and be used at the rarest of the rare cases.
Who can decide the case as the rarest of the rare case is the Senior Superintended Of Police of a station. If he/she feels that it is the rarest of the rare case, he can file case against any citizen. Of course, The court finally gives the verdict, but the threat to the freedom and the liberty of an citizen still remain under threat.