Iam seems very leen body please give me tips about
How to become fat body with in a month

You cannot become fat in a month.

Nor is it healthy

Nor is it safe.

Changing your metabolism is a difficult process that can not be completed in one month. Know that although you may hope to change your metabolism now, this will effect you for the rest of your life and your metabolism continues to slow as we age.

You didn't list any stats, but being lean is not a bad thing, but if you would like to build on what you have try increasing the protein in your diet. Body builders increase mass with certain diets, you can also look into those diets.

Why exactly would you want to become fat?

you cannot become fat in a month.

nor is it healthy

nor is it safe.

I am seems very lean,how to become fat?

Eat more meats, monitor you heart heart and blood pressure. Try protein shakes. If you lift weights, lift the max amount of weights you are able to lift, no more then 10 times. If you are able to lift more then 10 times, the weight isn't heavy enough to offer enough resistance and you'll be slimming, instead of bulking.