Patching after upgrade (windows 11gr2 -> 12cR2)
That would depend on what the "same" patches are.  At the very least, you'd need the patch specifically for the new version of the database.  But it could be that the the 11g patch fixed something in 11g that was inherently fixed in 12c.  You just have to look at each patch on a case-by-case basis.  Also, are you talking about individual patches or patchset bundles?  If the latter, simply apply the latest for your version of the database.