hai,
As your weight is less for your height. no need to worry. by taking healthy nutritive food you can gain weight.
eat protein nourished foods like Almond,cashew,channa,soyabean,peanut in your daily food intake.
Add jaggery,black gram,and dal prepared with ghee.
take diary product like milk,yogurt,chesse,butter etc. Add banana and tuber vegetables.

Dont take junk and high fat contain foods to gain food. that is not good for health.
This will nourish in a healthy way and gain weight. However being in a good health with stamina is more important than just gaining weight.

consult a nutritionist and dietician for proper advise to gain weight.

thanks and regards
Dr.S.Senthilnathan