@IvanMatala Completely in an FPGA? no. With an additional WiFi radio chip/module, sure (depending on if you can get the full documentation for your WiFi module). Is it cost effective compared to an off-the-shelf router? Nowhere close (FPGA solution will easily be 5-10x the cost in parts alone).
If you're considering this as a project, (based on some assumptions of your skill level from your question) it requires base skills that often can be filled by degree in Electronics Engineering (4+ years of study). After that, it would still be a very hard and expensive project.