I am preparing for CAT exam. In which colleges do i have to fill application form in order to take admissions later?

Through CAT exam your score will only reach to the IIMs for the programs you have selected while filling the CAT form. And only IIMs give you a call for next round if they fone you eligible and you make up in the merit list.

For the rest of the colleges you need to apply online. Every college opens an online application for a certain period of time. So you need to keep up with the timeline. IITs are generally filled after the CAT exam right after the CAT exam result is declared. Before the exam you need to fill for private colleges like FMS, S.P.Jain, MDI Guragaon, JBIMS Mumbai etc. These are just the few names many colleges will open after the CAT exam some of them as I mentioned above befor the exam.

Some of the colleges even conduct their own exams if you are looking forward to join those colleges then you need to fill.up the application and go through the entire selection process starting from the MBA exam. Some of them are IIFT for Indian Institute of foreign trade college (I think it's regustration date has already been closed), NMAT for Narsee Monjee, SNAP for symbiosis college.

So in short for any college other than IIMs you need to either give a separate exam or apply to these colleges with all your details before or after CAT exam depending on the applications time period.

All the best!!