Electrical and Electronics Engineering

For communication and other soft skills, it is better to do some course on Coursera or other online platforms. For technical skills, take admission in the course which is more interesting to you.

Hello Avadhesh,
It's very nice to see your dream of seeking admission in IITs or NITs. The situation is that IITs accept Diploma as equivalent to 12th but unfortunately NITs do not. Hence, tighten your belt and go all out with aim of clearing JEE Mains and JEE Advanced with good marks so that you will get admission in an IIT. Also, don't forget to score more than 75% in your Diploma.

Hi Gavinolla,
We are starting the new batch of CAO at Delhi.
You can enroll for this program.
Here are the eligibility criteria:
Age: Below 25 Years 6 months
Qualification: Graduate & above
Location: Delhi

There are plenty of career opportunities after passing Diploma in any branch. However, in the meantime and also with your job, doing AMIE is a better option.
About AMIE: http://www.amiestudycircle.com/about-amie.html
Admission in AMIE: http://www.amiestudycircle.com/amie-prospectus-admission.html