Do the jokes "Cheating is permissible when needed" or "Cheating is only permissible in the English exam" constitute mockery of religion?

Describing something as halal expresses a ruling of the Divine Law. Joking and lying about it means joking and lying about a matter of religion, which is a lie against Allah the Almighty, as He says: "And do not say about what your tongues falsely describe, 'This is lawful and this is unlawful,' to invent a lie against Allah. Indeed, those who invent a lie against Allah will not succeed."

Therefore, one must avoid and shun such joking. The matter becomes even worse if the speaker is dismissive of the Divine Law and its rulings, trivializing a part of the religion. In such a case, he combines lying about the Divine Law with mocking one of its rulings, as He says: "And if you ask them, they will surely say, 'We were only indulging in idle talk and play.' Say, 'Is it with Allah and His verses and His Messenger that you were mocking?'"

In summary: Joking with such words is dangerous, and one must warn against it and rebuke it.