Hello Arvind, Greetings!
Let me help you.
There are many things which you can do after completing B.Sc. It solely depends upon your interest:
(i) You can prepare for entrances like IIT JAM,I etc if you wish to pursue M.Sc. from premium colleges.
(ii) You can prepare for SSC CGL,UPSC CSE,CDS and other graduation based government exams.
(iii) You can pursue masters which will open more career options for you.
Thank you, hope this helps.