Hello dear student,
Greetings!!!!
It's not a problem at if any entrance exam is conducted in the month of January and 12th results are out in june ,as if this happens  then there's a provision of uploading your 12th results later once 12th results are out .
Entrance exams takes care of these things,  you don't need to worry about these things , just focus on your studies and there's management for taking taking care of these things.
Thankyou
Good luck