It can be done but it will require some modification. Here is a forum thread about someone who is running 27" tires on an early Celica for rally and off-road exploration:
http://www.expeditionportal.com/foru...hlight=JRally.
You will need some extra tire clearance. It can be obtained with longer suspension arms and taller struts in the back and/or some offset spindles in the front.
You will also want some gearing correction otherwise your engine will be out of its power-band and your car will be much less responsive. Also, your speedometer will read incorrectly. Changing to a lower gear ratio in your front differential (if you have a modern Celica) or rear differential (if you have a classic Celica) will help alleviate this.
Anything can be done, but it will likely require a lot of work, creativity, effort and resources to get everything dialed-in and working right.