The most important thing to understand migrating from 6.2 to (6.3,6.4 or 6.5) is that there is a mandatory repository migration step that must be completed before the upgrade.
EG : Step 4 in this link : https://helpx.adobe.com/ca/experience-manager/6-3/sites/deploying/using/upgrade.html
For 6.2 to 6.5 you need to :
1) perform all the necessary pre-upgrade maintenance steps
2) stop aem 6.2
3) unpack the 6.5 jar OVERTOP the existing crx-quickstart
java -Xmx4096m -jar aem-quickstart.jar -unpack
4) perform the mandatory repository migration to upgrade the segmentstore to oak-segment-tar. You need to get this right -- there are various profiles that are applicable depending on how your 6.2 is set up. So understand the different profiles and apply the correct one.
For example if everything is in the segmentstore tar files, and there is no datastore you would use :
java -Xmx4096m -XX:MaxPermSize=2048m -jar aem-quickstart.jar -v -x crx2oak -xargs -- --load-profile segment-no-ds
5) check the upgrade.log to see that the migration was successful. It will output this ASCII art COMPLETED at the bottom if it was successful.
6) perform the actual upgrade. this involves starting the 6.5 JAR without any startup scripts.
7) tail the error.log -- you will see the inplace upgrade happening on first start up.
enjoy
