If there is a patent for a product that has 16 claims and I sell a similar product and my product falls under 15 claims of the patented product but not the 16th claim then is it sellable? Or would I still get patent infringement notice?
Each claim is taken on its own. If your product meets everything laid out in any single claim then your product infringes that claim, and therefore infringes the patent.
You may have have heard that you need to have all elements of a claim to infringe - that is correct, all elements of any claim, not all claims.
You and your product may or may not attract the attention of the patent owner.