Hii sir I want to gain muscle

: Managment 
When we talk about how to gain muscle , we advise you primarily by follow good diet pattern by increasing of protein in your diet as meat , chest of chicken and avoid sweety food , start making sport as heavy lifting , running and gym in general which assist to increase size and strength of muscle with enough water drinking everyday about 2.5 liter daily  , then you can take some industerial protein drugs but i advise you to take it under medicl following to avoid any unbelivable complications 
: Advise 
Advise you to follow upright instructions and follow your improvment , and i confirm should do sport , good diet daily , and avoid stress life events