Short term

With B.Com, you can do tally or CCC, this will boost your chances of selection in bank. And, also open doors of being accounts manager.
Rather, you can join coaching for banking.

Hi Abhijit,
For information related to this, please follow the link:
http://www.ee.iitm.ac.in/2015/06/nptel-online-certification-courses/

ou can think of these courses with your graduation in B.Com programme :
Mutual fund research
Stock Market
Soft skills training
Foreign language
Digital marketing
Coaching for Bank exam
Certified Financial Planner
So choose the field according to your interest and caliber.
All the best!

Try to get a job. If you are wishing for just a computer certificate do any course in GST.

Hi,
There are many courses available but it's up to you and your interest. There are courses on graphic designing, Financial accounting packages, Basic programming, Hardware-Networking, HTML and CSS basic, Basic Cloud computing etc.
The mentioned courses duration is between 3-6 months depending upon the course content.