The 5 per cent stake sale would fetch about Rs 800 crore to the exchequer.
Floor price fixed at Rs 94 a share and it will be sold through a two-day offer for sale (OFS) beginning Wednesday.
Centre plans to sell three per cent in NLCIL, with a green-shoe option to sell another two per cent in the OFS.
The issue will open for institutional buyers on Wednesday, NLCIL said in a regulatory filing with stock exchanges.
For retail investors, the issue will open on October 26 and will get a further discount of 3.5 per cent.