critical house transit

Hi everyone

I just keep having the same doubt with different techniques:

should we consider a planet transiting its critical house when its transiting over the Bhava Cusp. or Rasis from Lagna?
For example, is Saturn critical transiting the 6th Bhava Cusp or 6th Rasi from Lagna even if it doesn´t fall with the 6th Cusp.?

thanks to all