I am a very skinny guy.... plz suggest me some diet to gain weight, and what should my daily diet? also i go to gym, can i take supplements?

If your BMI: Is less than 18 you may increase your calories, weight lifting.You may add nutritional shakes.If still unable to gain weight may see a doctor to rule out medical illness. Apetite stimulants may be prescribed if indicated.

Energy dense foods: To gain weight the healthy way, you need more calories in than you expend. Energy dense foods such as nuts and peanut butter will help. I suggest carrying nuts around and eating them throughout the day. They provide healthy oils and protein to build muscles.