There are lots of job options available for you after completing B.Tech Electronics and Communication Engineering. You can apply for the job in private companies as well as in the government jobs. Following is the list of government companies where you can apply:

Indian Space Research Organization
Bharat Sanchar Nigam limited
Jobs in Railway- IES Indian Engine Ring Services
Bharat Heavy Electronics Limited
Steel Authority of India Limited
Gas Limited
National Thermal Power Corporation
Electronics Corporation Of India Limited
BARC- Bhabha Atomic Research Center
UPSC- Union Public Service Commission
Indian Navy

You can also apply in following companies:

Tata Consultancy Services (TCS)
Infosys Technologies Ltd
Wipro Limited
Hewlett-Packard India Pvt. Ltd
IBM India Limited
Satyam Computer Services Ltd.
HCL Technologies Ltd.
Intel Technology India Pvt. Ltd.
CISCO Systems India Pvt. Ltd.
Patni Computer Systems Ltd.
Cognizant Technology Solutions India
HCL Infosystems Ltd.
Mahindra-British Telecom
Redington (India) Limited
i-Flex Solutions Ltd.