NBTC secretary-general Takorn Tantasit said the NBTC would have the draft published in the Royal Gazette soon and it is expected to come into force in the next two weeks.
The watchdog is expected to call the bid of the 24 licences in October or November.
Eight NBTC members voted in favour of the draft, while three voiced their opposition.
The NBTC will auction 24 commercial digital TV channel licences, of which seven are High-Definition (HD) variety TV channels, seven Standard Definition (SD) variety channels, seven SD news channels, and three SD children's channels.
The starting bid price of each HD channel is Bt1.510 billion and the bidders can raise price by Bt10 million per bid.
The starting price of SD variety channel is Bt380 million and the price can be raised by Bt5 million at a time.
The starting price of news channel is Bt220 million and the price can be raised by Bt2 million at a time.
The starting price of children's channel is Bt140 million and bidders can raise the price by Bt2 million at a time.