hi deep 

i think this question will get its best answer from yourself .i think you should chose the subject you are most interested in . since you ant to pursue bsc so it is also necessary to think about your future also . the subject becomes very tough in the final year so it would be better  to chose the subject you like most .however in terms of placements physics honours has a lead over geology . but there are other important factors too to think of 

best wishes