Which university is better DU, PU or Jammu University?

It entirely depends on which course you are choosing. However, overall DU is definitely better than PU and Jammu University.

The academics and faculty base are almost the same at these universities. However, academics are not the only influencing factor in the overall development of students. Curriculum, exposure, and other additional things also play crucial roles.  

At DU, you will have great exposure. DU has many societies like dance society, fashion society, debating society, etc. If you have any passion, you can explore it at DU.  The peer group at DU is also better. 

If we speak generally, for the given institutes, your preference order should be DU>PU>Jammu University.