Hi...

The certification courses can be done before or after pursuing MBA specialization in Finance.

Certification courses increases the value to your resume and it helps in placements for the students. It enhance the value of prospective employee and makes him out-standing. There are many sites which provide certification courses like:

Udemy

Talentedge

Coursera

edX

NPTEL

These sites provide various certification courses along with the continuous assessments providing assignments and exam at the end of the course. NPTEL gives the free course.

Some popular certification courses are:

Commodity Trading Certification

Debt Recovery Certification

Financial Services Marketing certification

Hedge Fund Certification

Anti Money Laundering and kYC Certification

Project Finance Certification

Credit Risk Certification

Mutual Funds Certification

Merger and Acquisition Certification

Portfolio Manager Certification

Treasury Markets Certification

Futures Trading Certification

FLIP Certification

I would recommend FLIP certification course will  be very useful for finance aspirants.

CFA is a good choice if you are eyeing on IBs

Financial modelling gives knowledge on equity, start up evaluation, credit risk management.

All the best