You don't seem to be familiar with protein shakes and all that. Drinking a protein shakes doesn't mean that you drink muscles. You need to work out. What happens when you lift weight and when you put your muscles under stress is that the tissue breaks down. So when it heals itself, it heals itself so it gets stronger than before. You repeat that process over and over again to build muscles. Protein is the building material for muscles. But you still have to be do the work. You could probably gain 15 lbs of muscle in a year but not without considerable amount of work.

I gained 30lbs in a year. So 15 in 6 months? Yes, its possible. But you'll have to lift plety of weights and that should be your main focus. It will be very difficult to gain that much with that much BJJ. Beware, if you gain 15 some of it will be fat. Theres no way to gain 15lbs lean muscle in 6 months.

You can't gain any muscle whatsoever with protein shakes. Additional muscle fiber is added in response to severe stress on the muscle being stressed.

protein and etc you ate cant increase your muscle without train. you can do train at gym or home training like push up variation and other.

I dont usually lift weights but am not opposed to it. i also roll bout 2 hours of bjj 5 days per week. can i gain that much in 6 months by just adding protein shakes to my diet? any help would be great.