I want to ceramic tile an existing concrete shower floor and need to know how to raise the drain in order to be even with the new floor?

What material is the drain and raiser. A lead and oakum joint can be raised without too much trouble. A plastic drain would have to have the cement floor opened up and the old drain cut out, the raiser extended and a new drain installed.
I much easier solution would be to keep the old drain in place and use beveled tile around it.
Good luck, Tom

If your shower has a double seepage floor drain the top part can be screwed up or down an inch or so. If you are removing the old tile it will be very easy for you to see if you have the double seepage drain. If you are not replacing all of the old floor you may have to break out a couple of inches around the drain to raise it up. Here are some images of a double seepage drain.

Find Tub & Shower Drains and other Shower & Bath Repair at Aubuchon Hardware