Learning a foreign language is basically a skill which opens a scope in accessing career in certain types of jobs like translator, interpreter, international conference facilitator etc.
There are many countries like France, Germany, Japan, Korea, Russia which are carrying out lot of business activities in their own language which is not English. These countries as well as our Govt departments dealing with them in matters of trade, business and diplomatic ties require interpreters or translators on many occasions.
B. Com has already equipped you with commercial and financial knowledge and the jargon used there. The learning of a language as a full fledged diploma level will definitely create an opportunity to look for jobs in this specialised area.
Please be in touch with job portals and newspapers and watch for the frequencies of these jobs so that you can have a feel of demand in this particular arena.
You can consider Arabic or French or Chinese or German also in place of Korean as the former also have potential in terms of getting a job.
Knowledge is power.