Clarifying the core difference between MBA and PGDM will help you understand which is better- MBA is a Degree awarded by universities and PGDM is a Diploma awarded by autonomous institutions.
As far as career growth is concerned, there is no difference between the two. It would depend on your performance rather than stressing on the fact whether you pursued PGDM or MBA.
Since PGDM courses are offered by instituitons, they provide an upgraded and industry oriented curriculum whereas in MBA, the syllabus is rigid which is not continously enhanced by the University also. Allthough it can be safely said that a degree from an affiliated university generates more brand value.
Companies do not differentiate between PGDM and MBA and both candidates are offered the same salary. So, the difference is not relevant in terms of career, ctc or further growth. But if you look at the curriculum offered then PGDM scores better than MBA as the syllabus is industry oriented and very up to date unlike MBA syllabus catered by the universities.
Hope it helps !