[Docs][TPU] Highlight TPU Software version selection (#22242)

Signed-off-by: NickLucche <nlucches@redhat.com>

docs/getting_started/installation/google_tpu.md

@@ -85,7 +85,7 @@ gcloud alpha compute tpus queued-resources create QUEUED_RESOURCE_ID \
 | PROJECT_ID         | Your Google Cloud project                                                                                                                                                                                |
 | ZONE               | The GCP zone where you want to create your Cloud TPU. The value you use depends on the version of TPUs you are using. For more information, see [TPU regions and zones]                                  |
 | ACCELERATOR_TYPE   | The TPU version you want to use. Specify the TPU version, for example `v5litepod-4` specifies a v5e TPU with 4 cores, `v6e-1` specifies a v6e TPU with 1 core. For more information, see [TPU versions]. |
-| RUNTIME_VERSION    | The TPU VM runtime version to use. For example, use `v2-alpha-tpuv6e` for a VM loaded with one or more v6e TPU(s). For more information see [TPU VM images].                                             |
+| RUNTIME_VERSION    | The TPU VM runtime version to use. For example, use `v2-alpha-tpuv6e` for a VM loaded with one or more v6e TPU(s).                                              |
 | SERVICE_ACCOUNT    | The email address for your service account. You can find it in the IAM Cloud Console under *Service Accounts*. For example: `tpu-service-account@<your_project_ID>.iam.gserviceaccount.com`              |
 
 Connect to your TPU VM using SSH:
@@ -94,6 +94,9 @@ Connect to your TPU VM using SSH:
 gcloud compute tpus tpu-vm ssh TPU_NAME --project PROJECT_ID --zone ZONE
 ```
 
+!!! note
+    When configuring `RUNTIME_VERSION` ("TPU software version") on GCP, ensure it matches the TPU generation you've selected by referencing the [TPU VM images] compatibility matrix. Using an incompatible version may prevent vLLM from running correctly.
+
 [TPU versions]: https://cloud.google.com/tpu/docs/runtimes
 [TPU VM images]: https://cloud.google.com/tpu/docs/runtimes
 [TPU regions and zones]: https://cloud.google.com/tpu/docs/regions-zones