Looking for cheapest possible room/shared flat for around 2 months May - June 2017

Hi ! I am a student of Mathematics, Applied Statistics & Computer Science at IIT Bombay, Mumbai , India. I  would be at IE Business School, Madrid, Spain for summer research project in May June 2017 and hence is looking for a cheapest possible shared/single room in nearby area. I can share culture of India and Asia and teach Mathematics/Statistics/English/Hindi/Meditation/Yoga/Indian food etc Indian stuff as well . I don't need lot of cool stuff to stay just basic things and I am fine with both  boy(not gay) or a girl, Spanish/French/Italian/English (any nationality)etc roommate. (S)he would  have a wonderful experience with this Indian flatmate ,that I can guarantee.