In the test, they are gonna ask you about the basics of architecture and civil engineering. there will be 50 objective type questions which you will have to answer in one hour.
In the interview part, they will ask you about your past experience and most important about your B.Tech/B.Arch project. if you have published papers in national and international journals then that will surely give you an extra advantage. besides that they will ask you why do you want to join SPA? what is your aim? they will ask you about your college too.