Does Copy will increase the reference count of object ?

The normal semantics of copy and mutableCopy are to give you back a retained object, just like creating a new one via alloc/init would have. They don't increment the reference count of the object being copied, if that's what you're asking. From the NSObject documentation for copy:

If you are using managed memory (not garbage collection), this method retains the new object before returning it. The invoker of the method, however, is responsible for releasing the returned object.