How to write in Punjabi

You can't write in any language on a photo in iPhoto, it's just not a feature of the app. You'll need an external editor for that.

In order of price here are some suggestions:

Seashore (free)

The Gimp (free)

Graphic Coverter ($45 approx)

Acorn ($50 approx)

Pixelmator ($50 approx)

Photoshop Elements ($75 approx)

There are many, many other options. Search on MacUpdate. You can set Photoshop (or any image editor) as an external editor in iPhoto. (Preferences -> General -> Edit Photo: Choose from the Drop Down Menu.) This way, when you double click a pic to edit in iPhoto it will open automatically in Photoshop or your Image Editor, and when you save it it's sent back to iPhoto automatically. This is the only way that edits made in another application will be displayed in iPhoto.

IamArunNirmal wrote:

How can I write in Punjabi on an image in iPhoto ??

If you are using a Mac, to write Punjabi you need to go to system preferences/language & text/input sources and activate the keyboard layout for Gurmukhi.

If you are using an iPad, there is no keyboard layout, but if your search in the app store for "punjabi" you may be able to find a keyboard that you can use via copy/paste.