B.A

No, one will not be allowed to get transferred from first year of one degree course to the other even in the same university. The logic for this is that a degree course is one whole of three years; one cannot take parts from two whole and create a new whole. Even if one was allowed what would that degree be known as? It will neither be a BA nor a BMS. Furthermore, these two courses are from two different faculties. BA is from Humanities & BMS from Commerce. There can never be any merger of two entirety different things.
However, if one has realized after spending a year in BA that this is not what one wanted to do, it is still not late. Even if one loses a year I would advice to start in the course one wants to do afresh. But before that decision, be sure what you want to do. In introspect, jot down the points that come to your mind, figure out the pros and cons of your decision and make an informed choice.
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