Bachelors

Yes students from all the stream are selected. I don't know who told you this but who so ever had told you he told you complete false information.

No, you have to choose a 3 year course that is B.Sc or BCA or BS+MS dual degree course same like B.Tech + M.Tech. You can go for 4 year B.Tech programme in any branch in which you have interest.
You have to appear for the entrance exam and have to qualify with a good marks and secure a seat. Best of luck.

You need to crack JEE for that.

See you can go for the books of psychology . You study them whenever you get time . You don't take too much pressure if you never read psychology , it's easy if you give your best . So study books . Start from basic.

Dear Sir / Madam,
Kindly note that EMBA is a post graduate programme. We have Advanced Diploma courses for Under Graduates. We can share the details for the same on your mail ID.
Regards
XIBMS Team

Please refer to the link provided below for a detailed list of courses from Viva Bharati University, West Bengal. Find admission process, eligibility, fees, rankings, placements, infrastructure and much more at this link. https://www.shiksha.com/university/visva-bharati-university-west-bengal-other-25287.