Answer : 3. "विमर्श 2023"
Explanation :

Solution: The inaugural event of Vimarsh 2023, a national hackathon focused on the use of 5G technology for police applications, took place in Delhi. The hackathon will consist of three phases of idea screening. Phases I and II will be conducted in virtual format, while Phase III will be conducted in a physical setting at designated centres. During Phase III, participants will have access to 5G testbeds, private networks and laboratories for their projects.