whats next step?
 

after giving written papers of css 2018 then in which month comes the interview ? what students do to prepare interview and whats next step to interview?

Go for the options
 

I think rather then waiting for the result you must find out your options. Whatever you want to do, may be a job (job interviews are helpful) etc. Along with that you can prepare you self for the interview.
Css 2018 result will be in October probably. So interviews are far away from now.