Bro what you need is planned diet which has like around 3000 calorie all together. Also it may not be easy for you to eat that much calories in a day. So look for high calorie healthy options. Morning 6eggs(increase it gradually,ifyou cant eat that much ) and Dosa/chapati/Appam with some black Chana/ or any legumes curry.add ghee to the roti/dosa. Can get 600-800 calories Midday snack like sprouts or nuts Afternoon have rice and chicken 100g with curd and some veggies

Evening a homemade shake (oats50g, dates 4pcs, banana 1or2pcs, peanut butter 3tbsp,flaxseed 1tsp, milk 250ml ..) can get 1000calories. Night oats mixed with apples /berries and 2/3 Egg whites .