How often do i have to do yoga and how long to achieve weight loss?

A long time: Yoga is good for you, but you need to burn up 3500 calories to lose a pound. Continue the yoga, do other exercise as well to burn up more calories, and eat less.

It depends: Weight loss requires burning fat which dependson howlong you exercise every day.It takes about an hour of daily exercise to lose a few hundred calories(200-400/d). At this rate it takes about 15-20 days to lose one pound of weight unlessy ou restrict your diet and cut calories that way which is much more effective in losing weight than exercise alone.So you have to do both to get the best results.