Yeah you can, perhaps assuming you are from General Category, you need atleast AIR 500 in either of JEE Mains or JEE Advanced to secure a seat in IISc Bangalore's B.S. Course, which again is very unpredictable. I believe a better option would be Qualifying KVPY SA or SX and accordingly secure admission at IISc Bangalore. The competition in KVPY is way lesser, though the main issue would be completion of syllabus at the time KVPY is conducted. Most of the Students yet dont complete their respective Class 11 or 12 Syllabus, but again there lies the challenge, and you even get a couple of chances. Even if you flunk in Class 11, you can reappear in KVPY in Class 12.