The collar of bacteriophage is differently located in class 11 and class12 ncert. Which is correct??

The picture on the left shows the neck of the bacteriophage which is not the collar, while the picture on the right has the collar correctly labelled. The single, pink coloured ring that you see just below the bacteriophage's head is where the collar lies, right above the neck, which is a series of green ring-like structures. Hope this answered your question, as required!