Business Management Studies

If you have interest in same field then you should do M.Arch else go for MBA. You need to qualify any entrance test (such as CAT / MAT/ XAT/ NMAT/ CMAT/ GMAT/ NEST) and should also have min of 50% to 55% in your Bachelors. You can do MBA in any specializations of your interest. I am listing below some of the common and most opted specialisation of the MBA course, international business management, agribusiness management, e-business/ e-commerce, financial market, entrepreneurship, finance, human resources management information systems marketing, operations, management strategic/ risk management, technology management.
Some good colleges are:
IIMs
Xavier's Labour Relations Institute, Jamshedpur (accepts XAT)
Lovely Professional University, Punjab (accepts / CAT / MAT / XAT / LPU-NEST Department of Management Studies, IIT Delhi
Indian Institute of Foreign Trade, Delhi (own test)
Management Development Institute (MDI), Gurgaon
Bharathidasan Institute of Management (BIM), Trichy
Narsee Monjee Institute of Management Studies, Mumbai (accepts NMAT)
National Institute of Industrial Engineering (NITIE), Mumbai
SCMHRD, Pune (accepts SNAP)
SP Jain Institute of Management and Research (SPJIMR), Mumbai
Shailesh J. Mehta School of Management, IIT Bombay
Tata Institute of Social Sciences, Mumbai (own test)
Pandit Ravishankar Shukla University (CAT/MAT)

No, it won't give you any trouble if you have already made up your mind. You need to qualify any entrance test (such as CAT / MAT/ XAT/ NMAT/ CMAT/ GMAT/ NEST) and should also have min of 50% to 55% in your Bachelors. You can do MBA in any specializations of your interest. I am listing below some of the common and most opted specialisation of the MBA course, international business management, agribusiness management, e-business/ e-commerce, financial market, entrepreneurship, finance, human resources management information systems marketing, operations, management strategic/ risk management, technology management.
Some good colleges are:
IIMs
Xavier's Labour Relations Institute, Jamshedpur (accepts XAT)
Lovely Professional University, Punjab (accepts / CAT / MAT / XAT / LPU-NEST Department of Management Studies, IIT Delhi
Indian Institute of Foreign Trade, Delhi (own test)
Management Development Institute (MDI), Gurgaon
Bharathidasan Institute of Management (BIM), Trichy
Narsee Monjee Institute of Management Studies, Mumbai (accepts NMAT)
National Institute of Industrial Engineering (NITIE), Mumbai
SCMHRD, Pune (accepts SNAP)
SP Jain Institute of Management and Research (SPJIMR), Mumbai
Shailesh J. Mehta School of Management, IIT Bombay
Tata Institute of Social Sciences, Mumbai (own test)
Pandit Ravishankar Shukla University (CAT/MAT)

Yes, it is good as it helps in better career growth. You need to qualify any entrance test (such as CAT / MAT/ XAT/ NMAT/ CMAT/ GMAT/ NEST) and should also have min of 50% to 55% in your Bachelors. You can do MBA in any specializations of your interest. I am listing below some of the common and most opted specialisation of the MBA course, international business management, agribusiness management, e-business/ e-commerce, financial market, entrepreneurship, finance, human resources management information systems marketing, operations, management strategic/ risk management, technology management.
Some good colleges are:
IIMs
Xavier's Labour Relations Institute, Jamshedpur (accepts XAT)
Lovely Professional University, Punjab (accepts / CAT / MAT / XAT / LPU-NEST Department of Management Studies, IIT Delhi
Indian Institute of Foreign Trade, Delhi (own test)
Management Development Institute (MDI), Gurgaon
Bharathidasan Institute of Management (BIM), Trichy
Narsee Monjee Institute of Management Studies, Mumbai (accepts NMAT)
National Institute of Industrial Engineering (NITIE), Mumbai
SCMHRD, Pune (accepts SNAP)
SP Jain Institute of Management and Research (SPJIMR), Mumbai
Shailesh J. Mehta School of Management, IIT Bombay
Tata Institute of Social Sciences, Mumbai (own test)
Pandit Ravishankar Shukla University (CAT/MAT)

1. Don't worry, look for options, take time and look for good options. Step in something that can help you start or do your business.
2. Would my Commerce counterparts have a upper hand over me?
Ans. Yes, they will only if you do not cover it up, there are coaching centers who provide you coaching & believe me anything you do by heart is easy and then you are from Science you will be able to get everything in that crash course or whatever you do to learn. You will get it, also you can use search engines to learn what you missed read books, consult your commerce faculty of school - I am sure they will guide you.
3. If you really want to do a business start looking for opportunities & courses related to that course also ask your friends and others, scratch the search engines. Look for courses and attend the counselling or any sessions that colleges provide.
4. I don't know what business you want to pursue with but as far as I know, I have my own relatives having business and they were Science students, do MBA or just start doing it or do a job after you are done of your graduation. However, graduation in anything is a must. So, try it out.