Mechatronics Engineering

Yes you can choose mechatronics after your Diploma in electronics as it is combination of both electronics and mechanical. It is a very good field. Also one can change the field of study after Diploma.

Modern production equipment consists of mechatronic modules that are integrated according to a control architecture. The most known architectures involve hierarchy, polyarchy, heterarchy, and hybrid. The scope is limited as of now but its growth would be tremendous. An industrial robot is a prime example of a mechatronics system; it includes aspects of electronics, mechanics, and computing to do its day-to-day jobs. With this specialization you can have good scope outside India, specially in a country like Japan.

mechanical is better