The registration for CAT has not yet started. It will start in the month of August. Once the forms are out you will get full details of the registration process online.  For getting into MBA you would need to clear the entrance exams i.e. CAT, XAT, MAT, CMAT etc...plus there are entrance exams for particular college eg. SNAP, NMAT.

Hi Mouni

Please specify the college or university in which you are interested to take the admission.

Hope to hear from you soon. :)