It's best if you let us know what you have to work with and what you want to accomplish.

Generally MIDI is a pretty straightforward routing.
MIDI out of of a keyboard follows a path to an input somewhere and then gets assigned so something that will generate a sound, or control an effect (or lights) etc.

How do you connect the MIDI out of your keyboard to the computer?
Whatever that is would be your MIDI Input Driver in RB.

Then you have 2 ways of assigning that MIDI to a sound; either the default VSTi synth, or a separate individual synth on a different VSTi port.

Ether way that VSTi synth has to be receiving the MIDI data (listening) on the same channel the synth is sending. It is possible to use multiple MIDI channels on a single synth and also possible to use a single MIDI channel on multiple synths. But if the synth you expect to generate sound is not 'listening' on the MIDI channel that your keyboard is sending it will remain silent.

There is good reason for this once you get everything working as expected; you may not want a given synth playing every MIDI event happening on every MIDI channel .. and if you do, you'll likely want different sounds from that synth for each MIDI channel. So synths listen for a MIDI channel and assign a sound to that MIDI channel.

One MIDI driver selection that often causes problems is using MIDIMapper. Selecting this driver means you are allowing Windows to 'guess' what your intent is and it does not usually work well with RB. It often interrupts the signal flow in an unwanted fashion

Better to use the MS GS Wavetable synth driver (even when you intend to use a VSTi in the long run) as this driver plays nicer with RB and follows your intended routing better.

Make your sound your own!
.. I do not work here, but the benefits are still awesome