Hello Sampath

There’s plenty of ways to go for post graduate. It’s all about your Interest and also betterment for your career.

Since you are interested in Mtech. I want to tell you that there are few specializations to name

VLSI System

Communication & Signal Procesing

Controls

RF

Embedded & Image Processing

Few Interdisciplanary Courses..

Out of all these VLSI has been good and will continue to be the best choice and often the toughest to get into. Cutoff's are generally high for VLSI as compared to other's.