There are multiple options. You just have to workout which option works for you/customer
- Setup 10.1, migrate all components/assets, test and cut over
- Migrate component wise
- IS and MWS to 10.1 that connects to Broker 9.6
- Broker to UM
While I would suggest second option, my question is why do you want to go with UM active active ? What is the need? Unless you have specific use case that requires UM a/a, you can always configure UM as a/p. Hey BTW, Broker is extended and supported so what’s the need of migrating it to UM? 
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