If he wants spamming in groups it certainly shows that his project is not good project. Now the ICO project has cost investors a lot, so I wonder why he is still looking for the Telegram group about ICO project. If he is brave I think he must make a promotion in this forum about his project.
he is the only person that can answer what will be the benefit for him participating in crypto popular telegram channel.
There are many ways to promote a project without the need to join in a large group but you need to use your own money for that.
Instead of joining why not an ads or open your Ann thread first here so members can review your project.