There are quite a few Institutions offering PGDCA. They are:

Jaipur National University

Meher Chand Mahajan Dayanand Anglo Vedic College

Prestige Institute of Management and Research

DAV College

Madras Christian College

Admission to PGDCA in all these Colleges is through Merit based. And if you are planning to do it from IGNOU, you can as well. To pursue PGDCA from IGNOU, you should have completed your Bachelor's degree of minimum 3 years duration in any discipline from a recongised University. But you should have Mathematics at 10+2 level or Graduation level. If you haven't studied Mathematics at both 10+2 or Graduation level, then you have to first pursue and pass BCS-012 course from IGNOU.  But if you have a college in mind, please do let us know and we shall help you with relevant information.