As far as 1st year students are concerned, they get vacations in December(one month) and then after their first year ends(i.e. Summer vacations for more than 2 months.).
For second year students, December holidays and then at the end of their 2nd years, they have to do PS1(internship). So they just get around 2–3 weeks.
Then 4th/5th year students also have to do PS2 in the summers. So they also get one month in December and around 2–3 weeks in summers.