Hi Nabarun, The answer to your question is yes, RRB do recruit SSE every year. Other than this they also recruit - Junior Engineer, Depot Material Superintendent, Chief Depot Material Superintendent and more. This year more than 4000 posts available for SSE but for 2018 no exam date notification updated yet. By this link keep yourself updated : 

https://www.rrbrecruitmenthelp.in/rrb-sse-recruitment/

Gud luck