Hair growth occurs from the hair follicles and so a tonsure - once, twice or even a hundred times will have no effect. Neither on the hair follicles, nor on your hair growth.
Make sure that you eat good food on time, drink lots of water, exercise, have fruits and vegetables , sleep atleast 6-7 hours, stay calm and stress
You may apply AMLA OIL atleast 3 times a week, half an hour before bath. Use mild herbal shampoos.