Will you please suggest me the names of some good courses after completing B.Tech in Electronics and Communication???

After completing B.Tech in Electronics and Communication you can apply for following courses:

M. Tech. Automotive Electronics (in collaboration with TIFAC-CORE industry partners)
M. Tech. Communication Engineering
M. Tech. Nanotechnology
M. Tech. Sensor System Technology
M. Tech. VLSI Design

If you are thinking for job then you can apply in following organizations:

Bharat Sanchar Nigam Limited
Bharat Electronics Limited
Bharat Electricals Limited
Oil and Natural Gas Corporation Ltd
Steel Authority of India Limited
Mahanagar Telephone Nigam Limited
Indian Space Research Organisation
Indian Oil Corporation