@NK7, I have just posted on your other thread but it makes sense to continue with this thread instead.
I echo what DMNCF said above.
If a Powerpoint presentation is suggested, stick with that, they have suggested a PowerPoint presentation for a reason. Don’t forget that your interviewers already know about NR because they are current employees but they want to know that you have taken the time to research and that you understand the concepts but don’t regurgitate everything from the NR website, you should also bring in your skills too to show that you are suited for that role.
I appreciate it’s a daunting thing to undertake but don’t be overwhelmed with the task in hand, I’d suggest you start your research on NR and the area that you are going to present on and make notes as you go along. I found it helpful having pieces of A4 paper to represent each slide and working from a rough draft before hitting the laptop and typing up my first draft.
Practice, practice, practice. Time yourself (my first presentation lasted less than 3 minutes so I knew that I needed to expand on everything and eventually I got the presentation to about 7 minutes). Practice speaking out loud, practice on family and friends. Slow down and resist the urge to rush through the presentation. And then practice your answers too, again out loud so that you get accustomed to speaking out loud. Don’t forget you’ve done really well to get to the AC stage so you are more than capable of gaining a role at NR.
I hadn’t really given a PowerPoint presentation before my AC so I researched what was expected from one and went from there. Ahead of the AC, I practiced screen sharing and I also printed a copy of my presentation out in case of technical hitches which fortunately didn’t happen.
I was in your position a couple of months back and fortunately was offered an apprentice role with NR and although the AC is daunting, I found the NR members really nice and they made me feel at ease.