Hello Anish,
Msc. Geology cutoff for BHU PET was around 315 out of 450 for general. If you are able to score around 300 then you are sure of your admission. You know there is also a BHU quota and employee quota. 25% seats are reserved for bhu students and 15% for employee son/daughter. There are less seats in msc. so give your best to crack the examination.
Hope this helps. Best of luck!