Hi welcome to HCm I have gone thru your query and found your weight is too low in proportion of your height . I can under stand your concern Dear ,If you want to gain weight and muscle, that is, lean muscle mass, you will have to start regimen of regular diet, including all essential nutrients eating right at right time, and often, and exercising regularly and increase your immunity . This means fulfilling your macro-nutrient intake (Carbs, Fats, Protein) and weight-training at least three time a week to as much as six times a week. Aim for up to 500 extra calories per day to start, and reduce the number if you gain weight too quickly or find you are gaining fat instead of muscle. You have to achieve a goal of minimum 70-75 kg . Warm up before you lift. Do not static stretch. Warming up will increase blood flow to your cold tight muscles prior to lifting. Engaging blood flow into your muscles prior to your workout will enhance performance and decrease risk of injury while training. With all above , Brisk walking ,Jogging , Running , Yoga shavasan in between the work outs . To stay healthy Pranayam ,meditation will help you attain a total blissfull physical and mental health ahead. This means fulfilling your macro-nutrient intake (Carbs, Fats, Protein , Water) and weight-training at least three time a week to as much as six times a week ,preferabaly under trained guide. Try to maintain realistic expectations throughout the process. Take care of your body. Get plenty of sleep. The body needs recovery time for muscles to grow. Aim for at least 7 hours of sleep every night. Avoid fried fast foods too much of sugar, tea, coffee ,alcohol , smoking ,stress ,constipation . Hope this helps solves your query .Take care , All the best . Don t hesitate to get back if have any further query .