Yes, you can definitely do BBA from Shaheed or any other college even if you are from science college. There are as such no norms by any college if you want to do BBA after science stream in 10+2.

BBA is not hard for anyone for any stream if they come in it. Many students do another course in graduation like B.Tech, BCA etc. and then they do MBA. If you want to come in the Business Administrative field then you can go without any tension. BBA is related to Business Administrative i.e. a managerial field. After doing MBA you will find the Managerial job in any company. If you have passed 10+2 then you can go for BBA and this stream is easy for you. Believe me as a fact you might feel the course a little difficult for first few months but later science stream students score much better grades than commerce students.

You can also do a BBA-MBA 5 Years Integrated course. In this, you can get the admission in MBA of 5 Years. You will take admission and after 5 years of continue reading, you will get the direct MBA degree. In this, you need not change your stream again and again. Many of universities in India offer this type of education.

Right now the best one is IIM Indore which conducts an exam of IPMAT, you can apply it now as applications are still open.

Feel free to ask if you have any more queries. All the best!!