Understand that the stock market is too (TOO!) big to be manipulated easily. It would require a lot of capital. But then again, when talking about Reliance Industries whose market cap is more than Rs 3.3 Lakh Crore, anything is possible. And not to forget the personal network and influence of Mukesh Ambani, indeed manipulating the market could be possible for them through insider trading.
Now coming to your exact question, yes, RIL was charged under India’s Prohibition of Fraudulent and Unfair Trade Practices Act back in March 2017 for manipulating the market and making unlawful gains. In the regulator’s order, 12 other front entities for the company were slapped with the same charge. They were all accused of coordinating market positions and trades in RPL shares.RIL was asked to pay $153 million as fine.
So yes, to answer your question, Ambani’s company did manipulate the stock market for unlawful gains. And they were decently punished for that.