Advocate Brajesh Kumar, appearing for some of the home buyers, said the court has asked Grant Thornton to give its preliminary report by December 14.
The apex court has also asked the auditor to place before it the draft terms of audit and timeframe within which it would be completed.
On July 5, the top court had asked a panel headed by former Delhi High Court judge S N Dhingra to proceed with auction of Unitech Ltd's unencumbered properties at Agra and Varanasi in Uttar Pradesh and Sriperumbudur in Tamil Nadu to refund money to the home buyers.
The court had set up a three-member panel for expeditious auction of over 600 acres of land of the real estate firm for refunding money to home buyers who do not want possession of their homes or flats.
Sanjay Chandra, managing director of Unitech Ltd, is seeking interim bail from the apex court after the Delhi High Court on August 11 last year had rejected the plea in a criminal case lodged in 2015 by 158 home buyers of Unitech projects -- 'Wild Flower Country' and 'Anthea Project' -- situated in Gurgaon in Haryana.