Any change in tyre diamter will affect speedo reading.. This means you cannot go any taller, but you can go with a wider tyre.

The closest is a 245/65/15... but this is an uncommon size and will probably be expensive. Also, you may have issues on full lock and with mounting this size tyre to your current rim.

Why did you want to increase tyre size? Do you go offroad?
To gain more clearance offroad and have better ability, a taller and usually wider tyre is chosen (such as 30x9.5x15) note the metric sizing, but this makes your speedo inaccurate.. as will any change in tyre diameter. It also makes the car accelerate slower and uses more fuel, due to the motor having to turn a larger wheel.

So in short, the answer is none.