Yes, after completing the B.Tech in computer science engineering you can apply for railway departments jobs conducted by the central government of india.

Job Opportunities in Indian Railways after B.tech CSE:
RPF Sub Inspector
Indian Railways Store Service
Indian Railways Service of Engineers
Indian Railways Traffic Service
Indian Railways Service of Signal Engineers
Sr.Engineer
Stenographer
Section Research Engineer.
Section Engineer.
Junior Research Engineer-I
Indian Railways Account Service
Sr. Engineering
Junior engineer
RPF Sub-Inspectors
Jr.Executive
Sr.System Analyst

Selection procedure:

Selection is generally done on the basis of --
Written examination
Physical test ( 1500 meters in 6 minutes )
Medical test

Main topics in written test are

General awareness,
English
Aptitude
Reasoning