There is no way to know now if you’ll ever need a PE license. Certain jobs require it. State law requires it before you can advertise your services as an engineer. There are three steps to getting a PE license: pass the Fundamentals of Engineering (FE) exam, work for four years, pass the PE exam.
Taking the FE exam is not a graduation requirement. However, there is no time in your life when it will be easier to pass the FE exam than when you are a senior in college. The exam covers fundamentals (statics, dynamics, strength of materials, etc.). Because no job requires you to use all of those, you will forget much of it in the years after college. Hence, preparing for the exam several years after college could be very difficult. (Think about having a fulltime job, and perhaps a family, and then finding time to review the fundamentals on your own. And after passing the FE exam, you would then have to prepare for the PE exam. People who have to do that sincerely regret not having taken the FE exam in college).
The fee for the exam and the time to take it will be the same whether you take the exam as a senior or ten years later. But the preparation time will be significantly different. Conclusion: You should take the exam.
Please visit the Tennessee Board of Architectural and Engineering Examiners website for more information about the Principles and Practice of Engineering Examination.