It is a given fact that IGNOU is one of the best universities in India. All of its courses have great value. But when it comes to PhD, the truth is that there are many universities that are more specialized in it. Also, you can opt to study abroad. It is a very good option and has a lot of benefits.
In the end, it’s your own personal decision. Just make sure to think about it open-mindedly first. You may refer to career counselling sites also. They give you the best advice regarding your career or any study-related decision.
Yes it is possible. There are a lot of mediocre students who evolve with time and end up cracking IIT or AIIMS.
Since MD radiology at AIIMS, New Delhi is your target, you will require a rank in top 3-5 to secure a place in MD radiology. It might be the toughest exam but it is not impossible. Try dedicating more time preparing for this, which might give you positive results.