Do we have to apply in b schools before giving cat 17 ?

As far as IIMs are concerned, there is a common application form for CAT and IIMs. But for other CAT participating B-schools, the application process starts around August September and goes on till February March for tier 2/3 B-schools. As far as top institutes like MDI, IMI, NITIE etc are concerned, their application process ends even before CAT is conducted. Hence, if you plan to apply in these institutions, you have to do so even before taking CAT.