Dear aspirant!!! I would like to inform you that yet the academic calenders are not out but if we consider last year the semester will start around 9th July and after 1-1.5 months you'll have your 1st internal exam which is called CAT-1 and then again after 1 month you'll have CAT-II and by the end of november you'll have the semester exams and from december your second semester will start. To know more refer to http://chennai.vit.ac.in/files/academics/calendar/Fall%202018-19.pdf

Hope that helped.Thank you