PGDM is equal to MBA because if PGDM is to be an equivalent to MBA then the college offering the PGDM course must have accreditation from AIU.
PGDM is because when an Institute is an autonomous body (meaning it is not affiliated to any University) and conducts management courses then such Institutes cannot offer MBA degree. Even IIMs, XLRI's doesn't offer MBA degrees they only give PGP Diploma or PGDM since they are autonomous and independent bodies. On similar lines AICTE (All India Council for Technical Education) is allowing approved colleges to run a PGDM course. Some Business Schools offering this AICTE PGDM course need not be autonomous, the PGDM course will be autonomous given by the Institute & directly approved by AICTE, Ministry of HRD, Govt of India.

PGDM is more flexible then MBA because the course structure is defined for MBA.
So you will have to decide what is your choice.
Hope this helps.
Good luck.