You have to pass HSC with a minimum of 55%. Here I am giving you a link where you get the list of colleges for B.Sc honours in Environment,ent science in West Bengal

https://collegedunia.com/bsc/environmental-science/west-bengal-collegeshttps://www.shiksha.com/science/colleges/environmental-sciences-colleges-kolkataFo r cut off and seat availability, each college publishes it in its own website.