As Mazin H Al-Hawaz and Nandeeta Samad have already written in their posts, it depends on the research topic and methodology. I often come across this question in conversation with my students. These were some of the advice I would give:
If you start researching a new area, then please also look for literature that is somehow related to your topic. We often dig to deep into a „research hole“ and forget to keep our eyes on the surface. In most cases, there are some giants which could be given more attention. Best way to do this: expand your keyword while browsing the meta databases (e.g. google scholar, EBSCO, IEEE, etc.).
Have a look also to other studies published in your field and discipline and get a glimpse on how much literature is usually need in a paper.
Do some research on meta-analyses in your field of research that are related to your topic. Be an explorer also of the list of references. I often find intriguing research while crawling through the references. This is called the „snowball research“.
Maybe, this is not the answer you expected, but I hope it is helpful to you.