choosing the appropriate NVIDIA driver for rhel 5.6

Hello,

I need to choose a driver for working on Red Hat Linux Enterprise 5.6, and as there is no redhat driver I need to choose an nvidia driver. My question is very simple, and any one who had worked with rhel 5.6 could have the answer, so I would be so thankful to get responsed. I need to know which nvidia driver works well with rhel 5.6. To be a little bit more precise, I should note that my main goal is working with Ansys software, which is a fluid mechanics software, and so the driver needs to be compatible with that as well.

Thanks for any help.