The threat of US sanctions forced India to look at alternatives to Iranian oil, which is among the cheapest. If the Biden government returns to the N-deal with Iran, from which the US had unilaterally walked out of under Trump, then, India can expect to resume oil imports from the Islamic republic, without the Damocles' Sword of US sanctions hanging over its head.
It may be recalled that the pact with Iran was one of the foreign policy highlights of the Obama government and Biden as his Vice President had played a big role in bringing it about. But the recent assassination of leading Iranian nuclear scientist Mohsen Fakhrizadeh, may experts believe, could tie Biden's hands by vitiating the atmosphere to such an extent that a return to the nuclear agreement becomes impossible.
However, even a partial improvement of US-Iran ties and removal of the sanctions on that country will see work on the strategically important Chabahar port will being speeded up as many companies that are now reluctant to participate for fear of US retaliation, will not face that constraint any more. This will boost India's strategic autonomy and give it more clout in the Gulf region as well as Central Asia.