Bsc physics is damn difficult and to study for Jee mains along with it will be too much difficult according to me .To cope up with both, may be you will end up with failure in both.So,I suggest you to drop a year and prepare for JEE, iff you will study hard and sure about yourself..That you can do better!!

One should focus at one only topic at a time(at least for studies) and if join bsc u need to give it time at least some..And if you join any non attending college then you might loose any imp info which might be given by teachers..So drop ONLY IF U R SURE THAT U CAN PERFORM BEST; otherwise continue with bsc and complete it from best college with full dedication…

Hope this will help..