The comments come within a month of NSE chief executive Vikram Limaye having said that the stock exchange intends to launch its initial public offering (IPO) by September.
"We are examining on legally... soon we will take a call," Tyagi told reporters on the sidelines of an NSE event, when asked about the IPO.
In an interview to PTI, Limaye had said NSE had approached Sebi for approval for the IPO.
"We have approached Sebi to seek its approval for the IPO and after that we will start the process of appointing merchant bankers, who will help the exchange in filing draft prospects for the IPO," Limaye had told PTI.
He said the bourse is hoping to launch the IPO by the third quarter of this calendar year and it is subject to approval from the Securities and Exchange Board of India (Sebi).
According to him, the entire IPO would be offer-for-sale (OFS), wherein existing shareholders will sell NSE's shares.
Last month, state-owned lender SBI said it is planning to offload 50 lakh shares representing 1.01 per cent stake in NSE to raise capital. Currently, SBI holds 5.19 per cent stake in NSE.
In December, IFCI sold its entire 2.44 per cent stake in NSE for Rs 805.6 crore.
Earlier in December 2016, NSE had filed its draft red herring prospectus with Sebi to launch its IPO. However, the plan was put on hold after investigations began into the co-location case. It was alleged that the exchange misused its co-location facility and gave preferential access to certain trading brokers.