Colleges in Tamil Nadu

No there is a direct admission in B.Sc course.It depends upon your marks in class 12th for admission. So stay updated with it and register yourself at the time of counseling.

Please refer to the link provided below for details regarding admissions in Anna University for integrated M.Sc. in Electronic Media. You can download their brochure which contains details regarding admissions, course eligibility, application dates, etc.
https://www.shiksha.com/university/anna-univer

No, Not any number. There will be many people with the same marks. At that time, in order to get the proper rank, they will use the random number system.
example: let's consider that the top mark of the entrance exam is 98 out of 100 marks and let 97 be the second followed by 96 as 3rd score positio

Sorry in Annamalai University, they will not grant you admission if you have not completed 10+2.
As per NCTE norms, regular teachers working in primary, middle, secondary or higher secondary schools in Tamilnadu, recognized by State / Central government, with a minimum of two years teaching experienc

Seems you know very less about engineering in India.
VIT is not even par with top 10 NITs and top 4 IIITs.
DTU, DAICT, NSIT, LNMIT, PEC and even Thapar are better than it.
Then how can you compare it to IITs.

Placement in VIT for B.Tech is very good specially for CSE and IT branches followed by civil mechanical, electrical and so on