Hi, shazia. Maintaining the proper amount of calories for weight loss can be a delicate balance. The minimum amount that you should eat per day is around 1,200. If you don't eat enough calories, your body will go into what is known as "starvation mode" and burn muscle instead of fat, which means that you won't lose weight and are losing muscle instead. And we all already know what happens when you eat
too many calories!
Many people eat anywhere from around 1,200 to 1,600 calories per day. You'll have to try and see what works for you. It has to be something that you know you can do for the rest of your life so that you don't regain the weight. I've found that 1,400 calories per day is a good amount for myself, as I'm not very hungry and can still lose weight. I always eat at least 1,200 calories per day. Also remember that you lose weight by burning more calories than you eat.
This site has a lot of good information for people who count calories (there's a forum for it as well), so have a look around.