Dear Lakshmi, with almost thousands of candidates passing every year as Physiotherapists and equal number of people faking their qualifications, it is important to have a body to bring together qualified physiotherapists under one umbrella. So by joining this association, you a regustered Physiotherapist with a license to practise. This association sets guidelines and ethical rules to be followed by professionals with independent practises ensuring fair practises. You can check the aims and objectives of IAP at: http://www.physiotherapyindia.org/about/iap-at-a-glance/3305-our-aims-objectives.html