Seperate Registration necessary?

An assessee who taken registration in Tamilnadu state sold exempted goods (printed books) within tamilnadu by way of conducting book fair in different places with in tamilnadu. Now they willing to conduct book fair in another state say kerala for sale of printed books. In this scenario, is it compulsory to take seperate registration for another state (kerala)? please give your valuable opinion in this regard is highly appreciated.