Blockchain of ADA can create a record keeping into the blockchain like luxury items or even normal items like cars ownership cert. land, or jewelries cert.?
Yes but other resources are also required, for instance a secure way of associating an identification code with the actual physical object.
so how I can start it? 
and my plan is clothing line
Others are already working on blockchain for supply chain, I’d say your first step should be to familiarise yourself with these projects. But basically you have to DYOR, not ask other people for their ideas! 
Okay noted! I dont copy anyway