I have done diploma in Interior Designing from Polytechnic college , SNDT n masters from UK. hOW can i become reg architect? any exam

how can apply for membership of IIA so that i can become member council of architecture ? do i have to give some exam or register my self in any course ( ie any correspondence course) i have an experience of approx 3 years in field of interior/ architecture. I used to job under registered architect.