I finished my diploma in electronics and communication engineering but i have backlogs can i join other courses like java and python?
Yes. Don't worry
You can clear the backlogs of your exam during summers going to your college all you need to do for the computer applications is getting enrolled in any course. I will suggest you to go for iOS and Iot workshops also any course on big data will help you a lot.
Python and Java are in trend you can learn those too.