Note: I also updated my BIOS on UEFI with the RTPs installed.
1) the BIOS has absolutely nothing to do with the RTPs, and anyone who told you otherwise has absolutely no idea of what he's talking about.
2) RTP is short for Run Time Package, and it means a package of resources required by the game.
That package is different for different makers - Ace-RTP is something other than 2003-RTP for example.
All official RTPs can be downloaded through the download links top right, and they can all be installed at the same time without problems.
3) to help you, you need to tell us which games and which RTPs you're talking about, preferably with links.
However, be warned that the older 2K(3) makers have been excessively pirated and that the different pirated RTPs are incompatible to each other as well as to the official RTP. And if you have games created by one of the pirated versions you'll be on your own to find a solution (and depending on what idiot used which pirated version there might be no solution at all, because any change to the RTP would destroy all compatibility as said above)