I dont know the reason though i entered everything correct for slot booking, I couldn't able to login , 

Hii

You may be entered wrong application number & password so that it shows invalid application number & password. You should check your registered gmail for correct application number. In your registered e- mail , a copy of succesfull registration mail has beeen present there. Or you may search your application by entering your details. 

Hope this information is helpful for you.