Engineer

A scientist is a person who has scientific training or who works in the sciences. An engineer is someone who is trained as an engineer. So, to my way of thinking, the practical difference lies in the educational degree and the description of the task being performed by the scientist or engineer.
On a more philosophical level, scientists tend to explore the natural world and discover new knowledge about the universe and how it works. Engineers apply that knowledge to solve practical problems, often with an eye toward optimizing cost, efficiency, or some other parameters.
There is considerable overlap between science and engineering, so you will find scientists who design and construct equipment and engineers who make important scientific discoveries.

This decade belongs to Electronics and Telecommunications. Electronics and Telecommunications will continue to impact all walks of life including business. Next wave of Industrial revolution is automation and Electronics will play a vital role in it. ECE engineers can be employed in all type of industries including IT. Computer Science is the facilitating technology for all business and personal activities. Indian IT industry is worlds largest outsourcing hub. Computer Science engineering is dominating the job market for last 15 years. Indian Computer industry has started showing early sign of decline due to outcry against outsourcing in western world. Therefore, Electronics &Telecommunication is best option with respect to career opportunities and scope. Computer Science will continue to good career option for some times in the field of Engineering. Mechanical is an ever green branch for last 50 years and will continue to remain same in next 50 years. Therefore my recommendations in order of precedence are ECE, CSE and then Mechanical engineering if student does not have any specific area of interest.