The ceremonies began on Tuesday and are likely to end early on Saturday amid support to the Guptas by Uttarakhand Chief Minister Trivendra Singh Rawat.
In line with an order by the Uttarakhand High Court, a 13-member official team is monitoring and video-filming some of the functions at the two high-profile weddings.
"We have told the Gupta brothers that there should be no damage to the flora and fauna of the region which is very close to alpine meadows," said Vaibhav Gupta, the Sub-Divisional Magistrate in Joshimath.
"But we are also giving them some space as it is a private function," he added.
Auli, a ski resort, is located at an elevation of 2,500 meters to 3,050 meters above sea level. Between June and October, the valley has one of the highest number of flower species anywhere in the world. Greens consider it a fragile ecological zone.
The wedding ceremonies have attracted many VIPs.
An Uttarakhand resident approached the High Court complaining against the makeshift constructions and the damage the weddings which some reports say could cost as much as Rs 200 crore would cause to the environment.
The Gupta brothers were in the news for their proximity to then South African President Jacob Zuma and alleged corruption. Their house in Johannesburg was raided by the police in February last year.
( With inputs from IANS )