Yes, the actual ICO starts on September 19th. White List (pre-sale) has alreayd started, and it's by invitation.
White List application for $5000+ checks is here:
https://ico.snov.io/#whitelistAre there any restrictions on joining ICO as KYBER, 0x projects? Do you have any information?
I saw only one restriction: citizens of Singapore and USA can't participate in it.
Any specific reason why citizens of these countries can't participate?
I am not sure about Singapore but it's very common that US citizens are not allowed to participate in ICOs. Although, no one really controls it, so any american who can use VPN can participate in ICO...