Which is better: MBA or PGDM?

I think you should go for MBA, because you can definitely get a better placement after that.

There is no difference between MBA and PGDM. B-Schools which are not affiliated to any university award PGDM. The degree of PGDM is equivalent to MBA as it's approved by AIU. You are advised to do MBA or PGDM from top 50 rank B-Schools or universities for a jump start to your management career.

PGDM is better if you get admission in top 20 colleges, otherwise go for MBA.