A fibroid measuring 1.2 cm in uterus wall so surgery is necessary or not?

Pain or bleeding? If you are not having pain or bleeding then fibroid surgery is usually not indicated as the fibroid is asymptomatic. The exception is fertility patients who have repeated miscarriages and the fibroid is located just under the lining of the uterus. (sub-mucosal fibroid under the endometrium)
Any symptoms? A fibroid of 1.2 cm does not warrant any treatment if there are no symptoms. If you are done with having children there would not be any reason to treat this. Soon you will be hitting menopause the fibroid is likely to shrink on its own.
For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form.
Practice safe sex, if you have sex.