Century Metal received the regulator's 'observations' on September 27, while the other two firms obtained them on September 28, as per the latest update with Sebi.
Sebi's observations are necessary for any company to launch public issues such as IPO, follow-on public offer and rights issue.
These companies had approached Sebi between June and July seeking approval to launch initial share-sales. Going by the draft papers, Aakash Educational Services will see sale of 1.85 crore equity shares by promoters.
The company provides comprehensive test preparatory services for students of classes 11 and 12 preparing for medical and engineering entrance examinations.
According to merchant banking sources, the company's IPO will garner Rs 1,000 crore.
Kotak Mahindra Capital Company, Citigroup Global Markets India, and CLSA India will manage the company's IPO.
The public offer of Century Metal comprises fresh issue of equity shares aggregating up to Rs 150 crore and an offer for sale of up to 64,02,650 equity shares of the company by promoters and existing shareholders.
The company intends to utilise the net proceeds from the fresh issue towards repayment of loan and for general corporate purposes.
ICICI Securities and Edelweiss Financial Services are the book running lead managers to the issue.
As per the draft prospectus, Ami Organics will see sale of 35 lakh equity shares. Funds raised through the IPO will be used for repayment of certain borrowings, to fund long term working capital requirements and for general corporate purposes.
ITI Capital is the sole book running lead manager to the issue.