Hm, when i look at the HP Drivers and Software support page for your 6200 Pro MT (Win8), i don't see any system firmware files that are available for this machine. But if i look at the same page and change the OS to Windows 7, this then shows the same BIOS version as in the link you posted. Why it's not shown for both OS versions i don't know?
In any case, that BIOS revision history does not go into great details about the BIOS capability, just what has been updated/fixed/added but it's worth noting that it references adding 'UEFI security support' in version 2.27 of the firmware. As such it must be EFI/UEFI capable in some way 
So, as your PC has an EFI/UEFI capable system firmware, usually you can set it up either as 'Legacy' boot (the old style BIOS with MBR based bootable disks) or 'EFI/UEFI' boot (new boot methods with GPT based bootable disks).
And if 'UEFI security support' means the firmware is secure boot capable, either the feature is turned on/off by the manufacturer OR by a user selectable setting in the firmware. But to use secure boot, you need a secure boot aware OS (like Windows 8 or later) and secure boot aware (UEFI) video card firmware (or else the system will never boot) 
But in your case, you have Windows 7 installed and if it is the HP operating system image that you use, the firmware is likely running in Legacy mode (although Win7 can be installed to GPT disks if firmware is set to EFI/UEFI mode).
And as Windows 7 does not support secure boot, it's likely there is a secure boot setting which is turned off in some way within the firmware. As such, you don't need a secure boot aware grahics card.
But in any case, UEFI capable graphics cards are supposed to be backwards compatible with legacy bios installs and also compatible with UEFI firmware when secure boot is disable for non secure boot capable OS's (non secure boot GPT installs).
So look at the settings within your system firmware and see what options you have in relation to Legacy/EFI/UEFI/Secure boot. Then look at the type of OS install you have (legacy MBR or EUEFI GPT). Lastly consider what you want to achieve.
Doing such will help you better focus your questions so that any answers you get are specific to what you are trying to do.