The share price of various Tata Group equities rose 36% last week. Stock in Tata Investment Corp declined 5%. Price of Tata shares: Some Tata group shares plunged 10% today (March 11). This follows reports that Tata Sons may not hold an IPO soon. Many Tata Group stocks rose 36% last week, becoming the four best-performing BSE500 stocks. Tata Technologies and Tata Consumer Products lost roughly 3%, while Tata Investment Corp fell 5%. Tata Teleservices declined 2%. Indian Hotels Company declined roughly 1%, Tata Steel and Tata Power Company fell over 1%. Also down: Tata Motors shares. The RBI has registered Tata Sons as a CIC. As a "upper layer" NBFC, it must list on exchanges within three years following notification. Tata Sons was notified by the RBI in September 2023 to list by September 2025.According to reports, Tata Sons' IPO could eclipse Life Insurance Corporation of India's ₹21,000 crore offer as the largest ever.