Hii!
You forgot to mention the name of the College or the University you are talking about in the question. Kindly Reframe the question and ask again including the necessary information.
The decision about the Internal exams and the dates are decided by the College or the University. So, you can visit the respective official website and check out the dates too. Else, you can ask your teachers to get an idea of the dates and the exam.
Hope you understand.
Good luck!