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is it possible to migrate 4.2f to latest version.Is there any in place upgrade
Definitely possible and encouraged.
If, by the second part of your question, you are asking "where to click" to make the upgrade happen, there is no such thing. Upgrades are a manual operation.
I would start by reading the Alfresco documentation on upgrades at https://docs.alfresco.com.
You can also check my guide to upgrade to Alfresco 6.
https://www.slideshare.net/angelborroy/2019-dev-con115angelborroy