Firstly, congratulations on successfully completing the VITEEE exam with flying colours. With a rank of 3906, you can easily get a CSE seat in Vellore campus in category 1 as the cut-off was 7000 in the year 2016. Just apply to their counselling process and you'll be able to secure a CSE seat in 1st category.

https://engineering.careers360.com/articles/viteee-cutoff

You can have a look at the cut-off trends of the previous years from the above link.

Hope this helps!!

All the best for counselling process