Shares of Jio Platforms, the telecom and digital services arm of Mukesh Ambani-led Reliance Industries, are set to make their stock market debut today, following India's biggest-ever initial public offering (IPO). Ahead of the listing, the grey market premium (GMP) of around 22% indicates a strong start for the Rs 30,213 crore issue, which attracted record investor demand.Jio shares are commanding a grey market premium of around Rs 246-247 over the IPO price of Rs 1,119, indicating a possible listing price of Rs 1,365-1,366.