minimum of 3 months
Any were between 3-10 years.
It depends entirely upon the school and the style that you are studying. In most cases it is 3 to 6 months to get from white belt to the first promotion. To reach black belt typically takes 3 to 5 years.
about3-10 years if you are Lucky
Research has shown that the green belt is 7th belt that can be achieved in Karate. One must achieve each level in karate in order to move up to the next level. Prior to achieving the green belt one would have to earn a blue, then a yellow belt, orange belt, blue belt, purple belt, green with white stripes belt and the next step would be the green belt.
it would take 3 or 4 years to get a black belt
That will depend on the school and style of karate. In some styles it is the rank just before black belt, in which case it would be around 3 years. In others it is the rank of a 9th and 10th degree black belt, in which case it would take you 40+ years.
It takes a long time to learn the material and you must KNOW it to get the belt Time frames vary from school to school. About three years is pretty normal.
It varies heavily on the school you go and how good you are at martial arts. It could vary from a few months to never if you can't memorize your forms. At my school if you gotten stronger you will pass to the next belt after a series of test. Also it depends on what belt your are right now. If your a white belt it'll take a few monthes if your good.
Depends upon the dojo and the organization. Most places have a minimum three year period to get a black belt. In my style of karate the average runs somewhere between four and five years.
if you are very good in its moves,then you can easily become brown belter in 1 and half year to2 year...
That depends entirely on the school and how hard one trains. It is typically 3 to 4 years of quality training.