This question has been requested quite a few times before. in my view, you need to better check some videos on youtube. they've greater details and offer you with a cautious steering.
Yes some of them are legit but not all the time because mostly they are scam. So if your going to invest in ICO make sure tou know all the details about it. Or else its better to find a ICO first then if you found a best one then you can invest to it. Also dont easily attract to there proposal that saying you can get higher profit from it once you invest to them because surely they are only convincing you but the truth is they are scam ICO.