This depends on the project development roadmap. After the project is completed, the ICO project token will be listed on the exchange for one month or longer. In the current market situation, the process of listing the tokens of some ICO projects is often delayed for some time.
The listing of the ICO token depends on the potential of this ICO project. I think the manager of ICO project will announce the day of listing on exchange floors so that you should be calm and wait for the day of listings, and recently, when the market goes down, almost ICO projects have delayed about listing on exchange floors because of the low price.