First thing I'd try is exporting the tracks from the Roland (digitally), setting the tempo in RB for the project, and importing the exported files to individual tracks in RB.

With any luck this simple method will work just fine.

If you can't export the files and have to actually 'record' them as audio into RB from the Roland, sync issues may be less likely, but the actual 'start' point will be the issue.
Either way, set the tempo first. Then use other tools if needed.

That way, attempting any other method to get a click will be easier in the long run.

There are videos around here about how to use the ACW to set a tempo map too .. very doable, even on older versions of RB.

I made a video many years ago that started with just a guitar track and an unknown tempo, then added RT's and Realdrums after the ACW did it's magic.. it's all very doable.

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