I would recommend selective reading of IGNOU material. Some of the topics have been crammed with information in these texts at the cost of clarity. They have copy pasted or put together parts from many texts thereby resulting in lack of cohesion between many parts of the text.
I had read the entire material. However, I wouldn’t recommend the same exercise to anyone. Best is to consult someone who has read the material previously ( Don’t ask professors. They would just look at the headings and tell you whether you read or not. From a competition point of view it is inefficient) and then decide what portion to skip and what to read.