Thanks for the query.
Firstly understand that muscle gain is very dependent on genetics and metabolism along with your daily diet and exercise routine.
It is important to know that just
eating just two heavy meals a day will not help.
Muscle gain is all about taking more nutrients than you use up. Eating the right foods at the right time is very important. There is no one food that helps muscle gain.
Eat meals at frequent intervals. You need to eat at least 6 meals a day.
Eat a protein rich mid meal between each main meal.
Pre/ post workout meals need a certain amount of carbs and proteins depending on your exercise routine.
Avoid junk, sugary, oily foods.
Include dairy, eggs, nuts, fruits, dry fruits, vegetables, whole grain
cereals, smoothies, masala milk, healthy oils in your diet.
Restrict eating sugary, sweet foods. Try to have healthy deserts like kheer, chikki or lassi.
Exercise at least 6 days a week. It helps development of muscle mass and improves appetite.
Even if you were to take just medicines or supplements they will not work in isolation. You need to have a nutrient dense meal and good exercise routine, it's crucial.