What kind of the job opportunities are available for me after completing B.E (Electronics and Instrumentation Engineering) in railway???

After completing B.E (Electronics and Instrumentation Engineering) you can apply for the Field Service Engineer jobs in railway. You can also apply for the following posts:

RPF Sub-Inspectors / Constables etc

Indian Railways Accounts Service (IRAS)

Indian Railway Store Service (IRSS)

Indian Railway Service of Engineers (IRSE)

You are eligible to apply for following government organizations too:

ONGC (Oil and Natural Gas Corporation)
ECIL (Electronics Corporation of India Limited)
Indian Telephone Industries Limited
Hindustan Machine Tools
National Thermal Power Corporation
Hindustan Aeronautics Limited
Bharat Electronics Limited
Bharat Heavy Electricals Limited