Dear Vikas

After BE in Mechanical Engineering, many streams of Mechanical Engineering are open to you for post-graduation. It is more important to figure as to which stream you are more interested in and which stream has more market value in today's date. Some of the interdisciplinary branches for MTech you can go for include: 

• Thermal Engineering (includes engines, heat transfer, thermodynamics, etc.)
• Design Engineering (aspect of design and application, methods of design, product design, etc.)
• Manufacturing and Precision Engineering (computational methods, microprocessors in robotics, etc.)
• Structural Engineering
• Renewable energy engineering
• Technology and Innovation Management
• Energy System Planning and Management
  
• Industrial Engineering
• Material Science and many more. 

Not all colleges offer all the sub-disciplines. Choose the stream based on your area of interest! 

All the best!