For the third and fourth semesters, I entered the incorrect generic elective—political science, actually—but I made the mistake of entering history, and now there is no editing option to correct it. Now what will happen?

Hi, it's fair to be anxious about your choice being entered incorrectly. Here is what you can do:

• The best line of action is to contact the university's examination or admissions department as soon as possible. Explain your mistake and ask for assistance in correcting it. Most institutions are aware of such difficulties and may allow you to make modifications if you notify them early enough. Look at Calcutta University's official website or any circulars given to students about elective revisions or adjustments. Sometimes institutions provide a grace period or a procedure for students to request revisions.  
• When contacting the university, make sure you have all of the appropriate documentation, such as verification of your accurate option selection or any relevant university communications. This can make the procedure run more smoothly. There may be a time limit after the original form submission to make adjustments. If the portal no longer accepts modifications, university officials may still be able to manually update your information.

Because there is no way to alter it on your end, and it is not an uncommon error, the institution should be able to handle this for you, especially if you notify them right away.

I hope this is helpful!