Humm ... this sounds interesting. Since it is a concentrate (water has been removed) you will need to add water back to it to get it near the level of the juice from the fresh fruits. From what I could find on pomegranate concentrates 1-qt of concentrate can make 6-8 qts juice - thats a 1 part concentrate to 5-7 parts water mixture. I would follow the instructions on the bottle you have. If you want to intensify the flavor a little, use a little less water.
Also, from what I have been able to find about using reconstituted fruit juices to make jelly - you'll need to use a recipe that uses added pectin (powered or liquid). I did a quick search on Google and found several here
- if you don't already have one.