HI,

First of all it depends on the board to which your school is affiliated to . The cutt off released by the college is for 3 boards namely, ISC ; CBSE and WB board .

For BCOM (hons.) morning (boys )

ISC - 93-95% 
CBSE - 95-97%
WB - 83-85%

For BCOM (hons.) evening section (co-ed)

ISC - 95-97%
CBSE - 96-98%

For BBA (hons.) evening (co-ed)

There is an entrance test for BBA and so the marks is on a 50-50 aggregate 
50% of boards mark + 50% of entrance exam mark

ISC - 66+
CBSE - 69+
WB - 61+

NOTE : The cut off provided is basically for the students belonging to the general category . For the reserved ones I can just say that the cut off is comparatively low .

GOOD LUCK