I want to block all website for specific users but want to give access skype for all users, how can i configure ? mainly skype application.
You need to identify the traffic with the ip firewall mangle feature and add a routing mark to the traffic. Then you need that connectons route to have the matching routing mark.
1) Unset "dns-name" for /ip hotspot profile. Use blank name there.
2) Make sure to use default HotSpot login page without any customization.