See in the official website its clearly given that you need to have a laptop or PC as your primary device and a Android or any OS smartphone as your secondary device. So you have to collect a laptop or computer in any way. You can borrow a laptop or computer or you can visit a Computer Cafe or any rental service to use the computer for the exam.

TO see the official guideline of VITEEE visit the link below:

https://vit.ac.in/files/VITEEE-online-guidelines.pdf

I hope my answer helps. All the very best for your future endeavors!