Colleges in Bangalore

You have to give entrance exams like CLAT for taking admission in a good college.

The basic eligibility is as:
Candidates must have passed an under graduate degree from any institution/university recognized by law in India or, candidates who have diploma in UG design from NIFT/NID only, are eligible or, Candidates who have passed diploma course of three years from NIFT/NID are also eligible.

Plain B.com is not a a difficult task, but if you go for B.com in finance and accountancy - that will be a perk for you as everything you study there you will come across the same in your CA course too and therefore your efforts will be lessened, Many students doing CA opt for Bachelor's in Accountancy and Finance (BAF). Also, BAF is more relevant to the field.

The RNS Institute of Technology accept only KEACET and COMEDK scores for admission to B.E. programs. JEE-Main result is acceptable for admission under management quota.
So, you have to seek the another college.

Hi Harika,
Follow the link given below for detailed information about the colleges of JEE Mains and their cut-off-
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor&ved=2ahUKEwjPs-iFqpTcAhWMRY8KHariB-kQFjAAegQIBBAB&usg=AOvVaw1N9BzFtyUCP4JU-2UQHQ0H
Good luck.