Dear,

You can do B.E/B.tech (4 years) which provides more knowledge related to your branch,grows opportunities for getting good job in terms of salary and your experience.You can directly do job after diploma if your score is more than 90% along with the deep practical and theoretical knowledge and good communication skills. The best short term course for students of Diploma in Electronics and Telecommunication Engineering are:

VLSI(Very Large Scale Integration).

Embedded Systems.

PLC.

Networking.

Circuit Designing.

Fibre optic technology.

You must try to do these courses from better Training institutes such as NIIT etc.It will be very advantageous for you regarding job placements.There are others too based upon your interest.

Hope this helps!