I know that units in besieged cities do not count towards province limit. Do they count when determining how many pieces you can place in a noncontrolled province in the new units phase? I have heard different things about whether or not cities even count for this, but assuming cities count, how about besieged cities?
Besieged units DO NOT count towards the province limit during Conflict or Overflow, but they DO count towards the province limit during Neutrals.
Besieged units do not count towards the total faction presence in a province during the Movement Within Provinces phase, but they generate New Units, if the faction of the beseiged units controls the city (holds the card), and count towards the number of units that can be added to a province. The main restriction of units under siege is that they can not be moved out of the city and they can not be reinforced with new units into the besieged city.
(Last paragraph corrected based on 3rd sentence of 6.14)