If you're driving the LX or LXi variants, then the stock tyre size would be 145/80 R13. You can go wider without changing the rim if you opt for 165/70 R13 but this is not a popular spec so your options will be limited. If you're ok with changing the rim, then you can safely jump to the VXi-spec 155/65 R14, which will give you one size wider rubber and one size bigger wheels.
If you already have a VXi, then 165/60 R14 is your safe bet. But this one too is a rare one to find.