Tata Ratan.
Explanation: The joke uses a play on words with “Tata” (a farewell expression, meaning “goodbye”) and “Ratan Tata” (the name of the famous Indian tycoon). The punchline “Tata Ratan” cleverly combines both meanings, as “Tata” can refer to his name and also act as a farewell, implying that it’s a goodbye to Ratan Tata. The humor comes from the wordplay and the light-hearted twist on a serious event.