While registering, I came across a field where I had to choose morning and afternoon session which consisted of Slat and design etc, I'm interested in management studies , so should I tap on the "none" option?

Thank you sir!

And btw , will the selection be based on my class 12 results as well or only the entrance

Class 12 marks will only decide the eligibility to appear for SET BBA exam. All the candidates will initially be shortlisted on the basis of their performance in SET BBA 2018 exam and later will have to appear for institute specific Group Exercise/Personal Interview/Written Ability Test rounds. After that they need to complete the admission procedure and get enrolled in the institute.

But I will be getting my 12 results by the end of May most probably

Thank you ma'am