Alambre visit
 

I only have 1 day in Seville and I am trying to decide the best time to book the Palacios Nazaries.Is it more efficient to see Charles v palace and Alcazaba Fort first and if so how much time should I allow to see these sites? I realize this is subjective ,but I need a general idea.

The Alhambra is in Grenada not Seville.
The Alcazar (which rivals the Alhambra), is in Seville.

The palace is part of the Alhambra which is MUCH larger and more extensive than the Alcazar and you could easily spend most of a day at that site alone.

It is, as was pointed out, in Granada, not in Seville. Granada is a three-hour train ride from Seville (probably faster to drive or take a bus).

The cathedral and Alcazar in Seville can easily take up a large part of one day depending on how thoroughly you wish to explore these sites.

But part of the Alhambra in Granada is indeed the Alcazaba, different from an alcazar. I believe and alcazaba is more of a fort, while and alcazar is more commodious, a castle.

I was in too much of a hurry when I posted my message. Actually I will be spending one night and one day in Granada and then traveling to Seville for two nights and one day. I would like to book a time slot for the Palcios Nazaries and I was questioning booking an early morning time say 8:30 or 9:00 seeing the palace first or booking a later time slot and viewing the other on site attractions first.

Since the palace is more or less at the other end of the Alhambra from the ticket office and entrance you might want to book a later time to see that particular section.

An Al-Cazaba houses the military officials; an Al-cazar houses the families, including the Sultan-prominent figure.

DCB, my personal preference is to see Palacio Nazaries as early as I could, hoping it won't be as crowded as later in the day. As I recall, there is no limit on how long one can stay inside and I stayed long enough to enjoy the palace. I also figured everyone coming in will start from the entrance.

If you expect to arrive at the Alhambra entrance gate at 8:30, I think a good time for the palace ticket would be 10:00. That way you won't have to race past the first half of the property to get there.
The Alhambra is a fortress-town, about a mile long and a quarter mile wide, with many buildings in addition to the Nazrid complex. You should probably allow at least four hours (or up to six) to soak in the atmosphere of the Alhambra and the adjacent Generalife gardens.
If you do not already have one, get a guidebook that has a map of the Alhambra before you get to Granada. That way you'll have a better idea of how the area is laid out and what to see in what order. Enjoy Andalucia!