Dear,

Now if you want to join directly after diploma then, the eligibility is that you should be a first class student.There are many posts available in ISRO for diploma students in electrical like Technical Assistant, Library Assistant, Scientific Assistant.Once the notification are out and forms are submitted online. You can apply through the website.

There is a lot of requirement in research organisations like ISRO, DRDO and so on, of a good research. So for the better future of india you should move on. I prefer you to do btech in electronics from a institute like thapar, iits or nits. and ISRO is approx giving information about requirements. Now if you want to join with ISRO ,then first you have to complete the Bachelor degree after the diploma. then you have to apply for ISRO exam according to post. If you are passed the written exam,then you are called for personal interview. you have also pass this interview,then you are the employee of ISRO .

Hope this helps!