The best thing to do here is to copy the files that the game uses into your project's folder and select "None" from the dialog box Game/Select RTP.
The files used in RGSS-RTP Standard are usually located at:
C:\Program Files\Common Files\Enterbrain\RGSS\Standard
Alternatively, if you use RPG Maker VX, the files used in RGSS2-RTP RPGVX are usually located at:
C:\Program Files\Common Files\Enterbrain\RGSS2\RPGVX
There you can copy the files that your game needs into your project's folder. To open the project folder, select Game/Open Game Folder.
Finally, copy the file RGSS102E.dll or RGSS202E.dll into the project's folder. This file is normally located at C:\Windows\System32.
After doing so, you can compress the game as usual.