Z:gnu-www-ja-stallman-mec-india--722cde-So you won't find all the pate/en

So you won't find all the patents that might threaten you but you'll find some of them. Then what do you do? You have to try to figure out precisely what these patents prohibit. That is very hard, because patents are written in tortuous legal language which is very hard for an engineer to understand. You are going to have to work with a lawyer to do it.