If you are opting for Polytechnic Diploma, there are several courses available.
Diploma in Computer Science: Where you would be dealing more towards the coding and scripting of the architecture and more deeply you would need to learn more about database storage.
Diploma in Electronics&Communication: it would me more detailed study about antenna, GSM network optical fibre transmission. Mainly related to transfer of communications and networking
Diploma in civil: it would be more dealing with the designing of any architecture. (here you need to have a drawing skills)
Diploma in automobile: deals with vehicle engineering, that is how a vehicle runs and its combustion
Diploma in mechanical: deals with mainly the turbines and combustion of the heavy engines, also hydraulics and its working and much more.
It would mainly depend on your interest which you would wish to choose since all the streams may take you to a different direction.