Hello,

There are various short term courses which you can consider doing after diploma in engineering such as computer hardware course, if you're interested in learning programming languages you can do that, there is also cisco network administration, other than this you can explore VLSI, robotics, PLC, fiber optic technology, SCADA, Big Data, Machine Learning, Data Science, Artificial Intelligence, Cyber Security, Cloud Computing etc, you can easily access various MOOCs regarding this such as edX, Coursera, Udemy, Udacity etc,