GENERAL CSE CORE-
If you find a professor whose name is starting “Gopi”, choose him right there without a doubt!! They are really great professors and are friendly too. I remember I had Gopinath and Gopichand for OOPS and another core CSE subject and I got A grades in both the subjects.
All teachers whose names are starting with Saira are really good and have great knowledge but again they are pretty strict. (VERY actually)
Theory of computation and Compiler design: Debi Prassana and Kannadasan are the best, literally THE BEST!! Uma Devi is also a great teacher and she will make sure you learn but yes you have to be in her good books and then she is the best person on earth.
NETWORKS-For networks, you will not have much choice but try to take Madhu Vishwanathan as he is a god sent a gift to every student. Gayatri, Shanthi are faculties who have a good knowledge of there field but again too strict.