You can sit for exams like CAT,XAT,GMAT,etc.Scoring good marks in these examinations is the key to getting admission in a good management institute.
You can go for MBA in finance or PGDM after B.Com. For post graduation courses you can try ITM Institute. It offers pgdm in various fields and one of them is pgdm in financial markets. The course is offered at the Navi Mumbai campus.