Dear student,

Your question is incomplete. You are talking about which exam. About which exam's eligibility criteria you are willing to know. Please tell the exam name for which you are seeking information.

If you are talking about any entrance exam then writing entrance exam will not effect your B.Tech course. You can write most of the entrance exams related to Engineering in final year during your graduation and you can continue your B.Tech.

Hope this helps.

Thank you!!