Is it possible to use multiple partition with the same route domain ?
It is recommended to configure each route domain in the separate partition in F5 LTM.
Yes, you can have multiple partitions using the same route domain.
Typically used to control administration of different environments within the same route domain.
Check out: https://devcentral.f5.com/questions/use-cases-of-routing-domain-and-partition-57935
Note that a partition will only see objects created in it and the parent. For example, if you have partitions mystuff-production and mystuff-test, both with parent Common and configured for route domain mystuff-rd, mystuff-production will see objects configured in itself and Common but not in mystuff-test.