Your repository appears to contain the contents of hugo’s public folder after running hugo. You are more likely to receive assistance on this forum when you share your entire project (the markdown, templates, etc.).
Looking at what you have shared I can tell you what is wrong. But without the rest of the project files I cannot tell you precisely why. In the furutre, when sharing a repository, share the entire project.
On your home page, served from https://quizinc.in/quizink/…
<a href="/quizink">
<img src="/img/portfolio/quizink.png" class="logo" alt="" />
</a>
The image src should be /quizink/img/portfolio/quizink.png.