Dual

If the college offers physics and maths degree together, then you can surely go for it.

Regarding placements, you will not be eligible for almost 80% of the companies which the B.Tech students are eligible for. This may/may not change by the time you reach your final year. So keep your fingers crossed.
But that being said, you will still get a lot of decent opportunities and that includes super dream offers (10+LPA) from:
Paypal
DeShaw
Morgan Stanley
Direct
Thorogood
SAP
Amazon, etc. and also dream offers (410 LPA)
Zoho
Hitachi
MuSigma, etc.

Regarding placements, you will not be eligible for almost 80% of the companies which the B.Tech students are eligible for. This may/may not change by the time you reach your final year. So keep your fingers crossed.
But that being said, you will still get a lot of decent opportunities and that includes super dream offers (10+LPA) from:
Paypal
DeShaw
Morgan Stanley
Direct
Thorogood
SAP
Amazon, etc. and also dream offers (410 LPA)
Zoho
Hitachi
MuSigma, etc.

A very common question, but as per the present situation, most of the business schools in India offering double specialisation. One for major and 2nd for the minor. Recently, I have seen a few business schools offering triple specialisation. Most of the top B-Schools of the country are offering dual specialisation.

Economics (including Micro Economics, Macro Economics, and Problems of Indian Economy),
Accounting (including Financial Accounting, Corporate Accounting, Cost Accounting, and Management Accounting),
Business Statistics and Mathematics
Business Organization, Management, Business Law, Company Law and Income Tax Law
General Knowledge and Current Affairs

Economics (including Micro Economics, Macro Economics, and Problems of Indian Economy),
Accounting (including Financial Accounting, Corporate Accounting, Cost Accounting, and Management Accounting)
Business Statistics and Mathematics
Business Organization, Management, Business Law, Company Law and Income Tax Law
General Knowledge and Current Affairs.

It depends on what you want to do. If you want to do Master's degree or go for higher education then integrated M.Com will be great. But if you are willing to join professional degrees like CA, CMA or CS then you should do B.Com (Hons).

Guru Nanak Dev University has a rich placement history. Also, dual integrated courses have seen a steady rise in placement. With that, all being said placement also depends upon the quality of skills that you acquire from the degree and how well you give the interview.