Is HA between rSeries tenant and classic BIG-IP VE supported?

Hello Amine_Kadimi,

Actually, it depends on the modules running and how the cluster is established.

For example, in TMOS images, LTM module using load-aware failover feature is not dependent of the hardware platform, so it's completely compatible. 

https://support.f5.com/csp/article/K8665

But you should take into account that other failover methods could not be working as expected.

In the other hand, APM module could have some incompatibilities clustering different HW platforms. 

https://support.f5.com/csp/article/K7040

So, in general, the response in 'yes', you can clustering different HW platforms.