Hi, After Bcom the specializations you can choose are:
1. MBA in Finance

2. MBA in Marketing

3. MBA in Human Resource

4. MBA in Banking

If the college/university provides the option of dual specialisation then you can opt dual specialisation in MBA Finance/Marketing so as to make the best use of the available job opportunities as dual specialisation helps to gather the basics of both the fields.

Hope this helps.
Good Luck.