New Delhi, May 21 -- Reliance Industries Ltd.'s plan to sell shares in digital arm Jio Platforms Ltd. - potentially India's biggest-ever initial public offering - is running into a thicket of challenges exacerbated by the war in Iran.

The conglomerate controlled by billionaire Mukesh Ambani has slowed preparations as it reviews the deal's structure in response to geopolitical tensions and market volatility, according to people familiar with the matter. The company still plans to file draft paperwork for the IPO and could pull the trigger at any time, though it has no firm date to do so, the people said, asking not to be identified to discuss private deliberations.

The Middle East conflict has impacted the share sale plan in multiple way...