can i get cse in vit vellore in first category with rank 27784 in vitee 2020
It is quite tough for you to get CSE with the provided rank in first category. Cutoff for CSE goes around 5000-8000 for students of first category.But you can definitely get other branches like EEE here.
Hope that helps;

Compare Colleges
College Comparison based on Courses, Placement, Rank, Fee