Based on available information, there isn't a single city officially designated or universally recognized as the "brave city" of Pakistan. However, Mandi Bahauddin is associated with bravery. Therefore, the response is:
While no single city holds the official title of "brave city," Mandi Bahauddin is a city in Pakistan with associations to acts of bravery, however it is not the official answer to this question.
Mandi Bahauddin is located in the Punjab province of Pakistan.