I’m 31 years old, unemployed, and with only a BCom pass degree from CU. What can I do to earn 50k pm in Kolkata?

Since you haven’t specified any previous work experience, I am assuming it to be zero or ur not interested in that line of work anymore. Since ur a B. Com graduate, I and still relatively young, may I suggest trying your luck out at doing some professional course such as that of a Company Secretary or Charted accountant. I don’t have much information about company secretary thus can’t comment on it much but even if ur able to complete C.A intermediate level, u will get easily earn decent income if you leave the course midway and do law so u have enough knowledge about taxation. Maybe someday you can be your own Boss. And if u become full fledged CA you will get decent income + respect. Maybe try Do a course of CFA, or simply do law.options are plenty. They simply depend upon your interest. But expect to earn substantially from the start.