Thesis writing is an important and a challenging task you will encounter as a graduate student. The thesis defense is the culmination of that process.

The thesis defense procedure may vary across institutions. By the time you are ready to present your defense, your thesis paper should be nearly complete, and some schools may require that your thesis paper be completely finished. During your thesis defense, you will be expected to present and defend your thesis in front of your advisor, faculty thesis committee, and other audience members – and to do so in a cohesive manner. You can expect to be asked a number of questions after your presentation, and you need to be prepared with the knowledge and skill necessary to answer the questions confidently.

Refer to the below URLs for tips:

 https://www.gradschools.com/get-informed/surviving-graduate-school/graduate-thesisdissertation/defending-your-thesis

http://www.erikmarshall.net/blog/10-tips-for-surviving-a-dissertation-defense/

A short video from Texas A&M University :