India

You don't specifically have to attend any competitive exam to get admission into degree course, however you would have to pass the entrance exam of the college you apply in.

Check the below link for operations management colleges accepting GMAT scores -
https://www.shiksha.com/mba/colleges/mba-in-operations-colleges-india?uaf[]=exam&ts=85114729&rf=filters&sp[]=385&ex[]=310&ed[]=et_20

You can consider following colleges:
SRM University, Chennai
VIT Vellore
NIT Warangal
IIT Hyderabad
IIT Madras
Karunya Institute of Technology and Sciences, Coimbatore
Sri Venkatswara University
TKM College of Engineering. Kollam
Christ University
Acharya Institute of Technology, Bangalore
Hindustan University
Veltech, Chennai

Hi,
Of course, you can apply to the course. Why do you think there will be a problem?

Best colleges in Maharashtra to pursue M.Sc in microbiology are as below.
1. Fergusson College, [FC] Pune
2. Ramnarain Ruia College, [RRC] Mumbai
3. Kishinchand Chellaram College of Arts, Commerce & Science, [KCCACS] Mumbai
4. Sophia College for Women, Mumbai
5. GN Khalsa College of Arts Science and Commerce, [GNKCASC] Mumbai
6. SIES College of Arts Science and Commerce, [SIES] Mumbai
7. BPHE Society's Ahmednagar College, [BPHESAC] Ahmednagar
8. Yashwantrao Chavan Institute of Science, Satara
9. Bhavan's College, Mumbai
10. Annasaheb Magar College, [AMC] Pune.

No, you cannot do that.you've to start again with 1st year if you want to change course . Make confident decision this time so that you don't have to think about changing things again.

Best colleges are:Ethiraj College for Women
Lovely Professional University
Govt. M.H. College of Home Science and Science for Women
Mount Carmel College
Pondicherry University
St. Mary's College,

Most of the government university in India is giving admission for M.Sc on the basis of Bachelor's Degree Percentage.

Maximum 50% or 60% is required in class 12th for SC candidate of Jharkhand state and to get B.Sc Agricultural.