No, you will not be able to do this exactly this way.
Maybe your operator uses USSD commands and implemented a way to activate data plan with them, then you can find where to execute them on Network > Mobile page.
Also, maybe your operator lets you activate a data plan with SMS? You can send SMS in Services > Mobile utilities > Messages.
If nothing from above is possible with your operator, please activate the data plan on your phone and reinsert the SIM back into RUTX11.