Hi,
I would not go 'Kill -9' on HANA services unless advised by SAP Support after deeper analysis.
SIGKILL will interrupt the process without giving it the chance to gracefully finish what is doing. This scenario oepn spaces for db inconsistencies as far as I can tell.
If you're trying to stop tenant dbs and that's getting stuck for some reason, try stopping the whole system from the SYSTEMDB tenant first. If you still face the issue I believe it's better to open a sap support incident to have a deeper analysis before going ahead and killing a process from the OS level.
btw: not sure if this is your case, but you might be seeing processes from the SYSTEMDB tenant in the OS level, which is of course totally fine. If you still see the hdbindexserver process belonging to your tenant after trying to stop it, then the approach above (system restart) should have an effect. However, restarting the system could erase the possibilities of having the root cause analyzed. Therefore, it is still better to create an SAP support incident. Take a few runtime dumps before doing so, and attach full system dump to the incident.
BRs,
Lucas de Oliveira