Honestly don't understand your question mate haha. If you get a chance to participate in the ICO, you can directly buy those tokens. It's usually quite simple just need to follow some direct instructions.

About exchanges, your question still does not make sense haha. If you are referring to trading the token after ICO ends, no one can tell you which exchanges they will be listed on except for the management team. Even though they know, most of the time they cannot even release this piece of info to public until closer to the date of the official listing (usually a few days before only). This is due to the NDA they signed with the exchanges. Besides illegally getting such information (eg: insider info), no one can tell you which exchanges will list so and so coin and its exact date as well way in advance. hope this helps