Just as we knew, R4isdhc 3DS RTS is a new card from r4i-sdhc.com to enable us press and hold the SELECT button while starting the game.
It will create an RTS file in your saves folder with the same filename as your NDS file.This new r4i card with many striking features,such as : working
directly on 3DS and DSi latest firmware without any updating, added RTG,RTS Features and so on.

And this article is a simple guide on how to use RTS Function on 3DS with R4i-sdhc 3DS RTS Card :

STEP.1 Go to game menu list

STEP.2 Select “ROM” (upper screen right hand side). User can activate/deactivate RTS features for that particular game. If you wish to keep the setting after shut down console, press “Save” button.

STEP.3 While play game, user can press hot-key “L+R+A+B” to enter the RTS menu.

STEP.4 Below is a RTS menu after pressing hot-key