hii KUMAR

like i would be the better person to answer for you !! to getin to top colleges in bangalore you need have minimum 50% of +2 but minimum wont make you fit in. so you need have pretty well score and if have writen KCET and having good rank in it you can get through them to univeristies. 

well let me consider you are non karnataka hence you can also get through the JEE mains for BTech while for BArch you can get in with NATA . you can also take seat with private unversites exam lile for PESSAT exam as well .

kindly refer top 10 colleges i have given below

• RV College of Engineering 
• BMS College of Engineering 
•  PES University [PESU]
• Ramaiah Institute Of Technology  [MSRIT]
• Bangalore Institute Of Technology [BIT]
• Siddaganga Institute of Technology [SIT]
• M. Visvesvaraya Institute Of Technology [MVIT]
• BMS Institute OF Technology [BMSIT]
• PESIT South campus
• Dayananda Sagar College of Engineering [DSCE]

hope this helps you much