I want to starts yoga exercise is it good for me to reduce fats and be strong? and is their any laws for eating meat?

Great: Yoga is excellent both mentally and physically. No laws against any food as long as you count it into the totality of your daily intake.

Yoga: Some eastern religions do incorporate both yoga and vegetarian diet in their practice, but unless you are following that religion, you can do yoga without becoming vegetarian (or be a vegetarian without doing yoga). Remember, yoga is more than just doing poses - it also includes deep breathing and meditation. Reducing fat, particularly saturated and trans fats, is a good idea in general.