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.