Step 1: Understand the terminology.
    
 INS: Stands for "Indian Naval Ship".
    
 Frigate: A type of warship. Frigates are generally used to protect other warships and merchant ships, especially from submarines and aircraft.
Step 2: Analyze the nickname "The Raging Rhino".
The one-horned rhinoceros is a powerful animal strongly associated with the state of Assam in India, which is home to the largest population of this species.
Step 3: Connect the nickname to the ship's name.
The Brahmaputra is a major river that flows through Assam. The Indian Navy often names its ships after rivers, mountains, and cities. INS Brahmaputra (F31) is the lead ship of her class of frigates. The ship's official crest prominently features a rhino, linking the ship's name (the river) with the iconic animal of the region (Assam). This association earned it the nickname "The Raging Rhino".