The question asks about the state fish of Jharkhand, providing four options to choose from. Let's analyze each option to find the correct answer.

1. Desi Mangur: The Desi Mangur (Clarias batrachus) is a species of freshwater catfish native to the Indian subcontinent. It is indeed recognized as the state fish of Jharkhand. This choice is accurate based on the official designation by the state government.
2. Kewai: This does not hold any known designation as the state fish of Jharkhand or any significant official status related to the state.
3. Jhinga: Normally refers to prawns or shrimp; in the state context, this isn't listed as Jharkhand's symbolic fish.
4. Katla: A well-known freshwater fish, but it is not the selected state fish of Jharkhand.

Based on the analysis, the correct answer is Desi Mangur. This is officially declared as the state fish of Jharkhand.

Conclusion: By understanding the biological and cultural significance attached to the species in question, we determine that Desi Mangur is the correct response, aligning with Jharkhand’s state government announcements and recognitions.