Your chances of admission to a PGDM program in marketing will depend on several factors, including the specific program and its admission criteria, as well as the number of applicants and the competition for admission. A percentile of 66 in CMAT exam in the general category is a decent score, but it may not guarantee admission to the top-ranked institutes. However, there are many good PGDM programs in marketing that you may be eligible for. To get a better idea of your chances of admission, you should check the admission criteria of the PGDM programs you are interested in. Many institutes also consider factors such as academic background, work experience, extracurricular activities, and performance in the personal interview and group discussion rounds. In addition to your CMAT percentile, you should also focus on building a strong application that highlights your strengths and achievements. This could include showcasing your academic performance, highlighting your work experience and leadership skills, and demonstrating your interest in the field of marketing. Overall, while a percentile of 66 in CMAT exam in the general category is a good score, admission to PGDM programs in marketing is competitive, and there is no guarantee of admission. It's important to research different programs, prepare a strong application, and have realistic expectations about your chances of admission.