I am in final year of electronics and communication engineering. so which software languages which I must know?

Answer 1

(Edited)
Websites
HTML
CSS
JavaScript
PHP
JQuery
SQL

databases
SQL
PhP

Hacking:
Python

App development:
Java
Corona
HTML/CSS(web application)
C#

IOS : Swift

Game :
Python
Java
C++
C#

http://www.androidauthority.com/want-develop-android-apps-languages-learn-391008/

Answer 2

and maybe Erlang for networking